de1archives

DE1 Archives

CHARLES BABBAGE'S

DIFFERENCE ENGINE NO. 1

SURVIVING ARCHIVES

AND OTHER SOURCES

Compiled by

C.J.D. Roberts M.A.

A. PRINCIPAL COLLECTIONS

Science Museum Library,

Imperial College Way,

South Kensington, London SW7

Notes on the Drawings of Babbage's First Difference Engine

in the [K] and [U] Series

General Notes

Drawings in the [K] Series were rediscovered in modern times at King's College University of London, where they had been deposited by the Government in the Summer of 1843. They were transferred to the Science Museum Library in 1971.

Drawings in the [U] Series were donated to the Science Museum by Major General Henry P. Babbage (Babbage's youngest son) in 1905.

THE [K] SERIES

Reference: [K 1] Folder 1

Size: 35 7/16" x 20 27/32"

Caption: End View of Printing Part nearly all of which has been altered since this was drawn.

Watermark: None

Condition: Very dirty and bottom edge torn. The centres of the various wheels drawn on it have been patched with small pieces of paper.

Notes:

No date. Drawing comprises a single figure: viz. an end view of the printing part for an early version of DE1. Details on this drawing should be compared with those on drawings [U2[a&b]].

Reference: [K 2] Folder 1

Size: 36 1/4" x 25 1/4"

Caption: Endless screw, clutches, &c. &c. for moving the copper [plate]

Watermark: J. Whatman 1831

Condition: Dirty and torn edge. Some grease spots.

Notes:

This drawing comprises several figures illustrating the details (plan, elevation section etc.) of the Endless Screw Wheel, levers, cones and other mechanisms which are used to move the Copper Plate from figure to figure across a line of results in the table being punched by DE1. Details on this drawing should be compared with those shown on drawings [U7] and [K11].

There are also a number of rough pencil sketches on the drawing.

Reference: [K 3] Folder 1

Size: 47 1/4" x 27 1/2"

Caption: Frame for holding the copper [printing plate]

Watermark: J. Whatman Turkey Mill Kent 1824

Condition: Torn and mouldy

Notes:

No date. This is a drawing (plan and section) of the frame which holds, stretches and keeps flat the copper plate upon which are stamped by punch the results of DE1's calculations. It seems to work like a vice for very clearly shown is a device for adjusting the position of a smaller frame within a larger outer frame. The screw is shown having 20 threads per inch.

There are also some rough pencil sketches on this drawing as well.

Reference: [K 4] Loose

Size: 36 3/4" x 54 1/8"

Caption: 3 Fig[ure] Motion [Device]

Watermark: None

Condition: Torn, torn edges, relatively clean

Notes:

No date. On the face side of the drawing are details (side, top and end views etc.) of the 3-Figure Motion Device. This is the device which allows the first 3 (or 4) significant figures of a result to be punched when at the beginning of a line. Among the details shown are the arms fixed at the base of the Table's Difference Carrying (Figure Wheel) Axis which trigger the Device. On the back side of the drawing are detailed drawings (plan, side view etc.) of the Type Sector and its Axis.

Note and amendment on drawing in Babbage's handwriting referring to the lever which connects this device to the printing control mechanisms:

"These levers, detents &c. will not now be wanted; their work is done by the returning crank. May 18 -1832."

Reference: [K 5] to [K 10] Missing

Reference: [K 11] Loose in Map Press Unit (cf also [K100])

Size: 90 3/4" x 45"

Caption: None

Watermark: None

Condition: Relatively clean, torn edge, torn where it has been folded (4 times).

Notes:

No date. This is a large drawing comprising a plan view over the driving and printing part of DE1 showing all the drive and control mechanisms. Similar to [U7] which is a copy. Parts nearest the driving handle have been drawn faintly in pencil. This is one of the more important drawings of DE1 to have survived.

Several amendments in a heavy ink have been made on this drawing.

The parts, Spiral Axis and Ribbon Axis, have been labelled as such.

Reference: [K 12] to [K 26] Missing

Reference: [K 27] Folder 1

Size: 39 1/8" x 26 3/16"

Caption: Plan of Machinery intended to be attached to planing machine

Watermark: J. Whatman 1826

Condition: Illegible, in pencil only. Oil marks. Damaged and fragile.

Notes:

No date. The purpose of the parts on this drawing have not been identified.

Reference: [K 28] Missing

Reference: [K 29] Folder 1

Size: 38 1/4" x 27"

Caption: 60-wheel and levers - old plan

Watermark: J. Whatman 1826

Condition: Dirty. Some oil and grease spots.

Notes:

No date. Drawing is a plan and section of an early version of the 1st 60-Wheel and the intermediate/communicating wheels which drive the 2nd 60-Wheel (shown in section). Also included are detailed diagrams (section, side view etc.) of 2 levers. Some pencilling.

Note on drawing next to the Sine-Qua-Non Wheel.:

"This sine qua non wheel to be altered. It now moves by 20ths instead of 24ths. Jan^y 1832."

Note on drawing adjacent to the 60-Wheel:

"When a 20-Wheel had been substituted for the 24-Wheel other 60-Wheels were drawn. They are now lighter".

Reference: [K 30] Missing

Reference: [K 31] Folder 1

Size: 39" x 26 7/16"

Caption: Calculating Machine. Details of various wheels.

Watermark: J. Whatman 1826

Condition: V. dirty. One large oil spot. Centre of wheels damaged by dividers/compass points.

Notes:

No date. Appears to be figures (end views, side views etc) of an early version of DE1's 24-Wheel [Printing Axis control] mechanisms, in which case the details on this drawing should be compared with those on drawings [U1[a&b]], [U2[a&b]], [K78] and [K1].

Various wheels, including Locking or Roller Wheels and Stud Wheels with 12, 20 or 24 teeth scallops or studs shown on them, have been drawn. Shown also at the bottom left hand side of the drawing are figures (side and end view) of a driving wheel and its driven partner (unidentified purpose) both with starting teeth and the plumbing block which keeps them in position on the axis.

Reference: [K 32] Loose

Size: 26" x 39 1/2"

Caption: Motions for decimal point &c.- Old plan: taken off board July 1831.

Watermark: J. Whatman 182[?]

Condition: Some oil marks, frayed edges

Notes:

No date. Detailed drawings of the parts (levers, springs, 24-Stud Wheel, ratchet wheel, adjusting knob etc.) controlling the positioning and punching of the decimal point in the early version of DE1. Apparatus superseded in later (1833) version of DE1.

Reference: [K 33] Folder 1

Size: 38 3/8" x 25 3/16"

Caption: Type Sector. Various cams and details.

Watermark: J. Whatman 183[3?]

Condition: Oily and dirty, some grease spots.

Notes:

No date. Details (plan, section etc.) of the Type Sector, the Cam (for raising/lowering/steadying the Type Sector, i.e. vertical motion?), Cam (for causing the Type Sector to swing in/out i.e. circular motion?), the Mitre Wheels which drive the Cams, and a Plumbing Block which supports the shaft around which one of the Cams rotates. The Type Sector itself is held in position by three screws on a tongue fitted to the Type Sector Axis, and it therefore appears that it is exchangeable for another which has punches of a different size or typeface fitted to it.

Various parts on drawing struck out as "not wanted", (in particular that Cam which causes the Type Sector to swing in/out?) and its Sector Wheel at the base of the Type Sector Axis.

Reference: [K 34] Folder 1

Size: 38 11/16"x 25 3/16"

Caption: Forcer of punches.

Watermark: J. Whatman 1828

Condition: Frayed at edges, in pencil and indistinct.

Notes:

No date. The upper end of a Punch appears to be able to fit inside barrel of the Forcer. Springs to return forcer after punching are clearly shown.

Reference: [K 35] to [K 39] Missing

Reference: [K 40] Folder 1

Size: 37 1/4" x 25 3/8"

Caption: No caption

Watermark: J. Whatman 182[8?]

Condition: In relatively clean and good condition

Notes:

No date. This drawing is a plan view of the first three Difference Axes (Table, 1st and 2nd Difference) of the calculating part of DE1. A vertical section through a calculating cage is also shown. Drawing shows in considerable detail the general layout of the Figure Wheels, Calculating Axes, Bolts, a Snail Wheel on the Table Axis, the spiral of Bolting Arms etc., etc.

This is one of the more important drawings to have survived.

Notes made on drawing:

Re the bolting arms: "This was drawn from directions in a written memorandum but the position relative to the highest bolting arm seems to be wrong."

Re the Eccentrics/Lockings Axis: "The Direction in which this moves is reversed by the alteration in the 20 Axis."

Reference: [K 41] Missing

Reference: [K 42] Folder 1

Size: 38" x 25 5/16"

Caption: Levers for cones, single teeth &c. &c.

Watermark: J. Whatman 183[1?]

Condition: Some smudges and dirt otherwise relatively clean.

Notes:

No date. This drawing shows the details of single teeth on the First Axis which drive the 1st and 2nd 20-Wheels, their starting orientation and also the Key and the end of the lever which slide them horizontally along the First Axis in and out of gear with the wheels that they drive.

Also shows details of the levers which squeeze the Cones on the Endless Screw Mechanism for Figure to Figure Motion (see also drawing [K 2]).

Reference: [K 43] Folder: 2

Size: 24 3/4" x 38 1/8"

Caption: 3 figure motion

Watermark: J. Whatman 1828

Condition:

Notes:

No date. This is a detailed drawing (plan, section, side view etc.) of the 3-Figure Motion device. It shows clearly the trip arms fitted to the Result Axis' Figure Wheel/Carrying Axis just on the top side of the Upper Platform. The spring which returns the arms after they have been acted upon is fitted to the General Platform. Also shown are the levers upon which these arms act.

Reference: [K 44] Folder: 2

Size: 25 1/2" x 38 1/2"

Caption: No caption

Watermark: J. Whatman 1831

Condition:

Notes:

This drawing comprises details (end views and sections) of the 2nd 20-Wheel group of mechanisms.

Also drawn are the two pivoting cranks which drive the ratchets on the Ratchet Wheel Axis of the Endless screw mechanism for Figure to Figure Motion.

Figures on drawing from top left (scanning from top to bottom of page then left to right):

i) in section the Ratchet Wheel (Long Eccentric) and the Arm which holds its Claw

ii) end of Pivot (Long Eccentric) which moves the Claw

iii) top view of Claw

iv) side view of the Ratchet Wheel (Long Eccentric) on its Axis and the Pivot Crank which drives it from the First Axis.

v) [from top of drawing again] section through 2nd 20-Wheel mechanism (a) Arms (fixed on the 20-Axis) which drive the 2nd 20-Wheel forward which engage suitable arms on the 3rd component of the 2nd 20-Wheel mechanism, i.e. the Stud Wheel which moves the Starting Teeth for the Great Wheel. (b) the second wheel on the Boss of the 2nd 20-Wheel, which has studs on both sides, i.e. that Stud Wheel which controls the movement of the Shades on both the (Long and Short Eccentric) Ratchet Wheels which control the movement of Figure to Figure Motion via the Endless Screw mechanism. (c) the 3rd component of the 2nd 20-Wheel mechanism, i.e. the 2nd Sine Qua Non Wheel (fixed part) for Cones, which also has the 20 teeth by which the whole of the 2nd 20-Wheel is driven by a single tooth on the First Axis. Note the long tooth on this wheel for allowing horizontal for and giving circular movement to the Movable Part of this Sine Qua Non Wheel.

vi) end view (from calculating end of DE1) of 2nd 20-Wheel group of mechanisms. Note 3 teeth of the 3rd 60-Wheel shown. Note how the 2nd 20-Wheel mechanism acts on levers which control shades on the Ratchet Wheels which allow their claws to be engaged or disengaged from their (24 toothed) ratchets. Note the Spring and Roller Wheel which locks the group of 20-Wheel mechanisms (20 positions, loose locking). Note the Single Tooth on the First Axis (also shown) in this drawing is rotating clockwise, hence the 2nd 20-Wheel and its components will move anti-clockwise in this drawing.

vii) [from top of drawing again] two figures of sections through the Short and Long Eccentric Cranks which move the Claws on the Ratchet Wheels on the Ratchet Wheel Axis.

viii) [from top of drawing again] end view of the 2nd Sine Qua Non Wheel on the 20 Axis, both the Fixed and Movable Parts, which causes the Male Cones on the Endless Screw Wheel mechanism to engage and disengage the Female Cones.

ix) section through the Movable part of the 2nd Sine Qua Non Wheel, note that its boss has short Arms by which a lever moves it horizontally along the 20-Axis to engage the Fixed Part of the Sine Qua Non Wheel.

x) [slightly to left] top view of Claw for the Short Eccentric Ratchet Wheel.

xi) section through the Short Eccentric Ratchet Wheel and its Arm which holds the Claw.

xii) [on the extreme right hand side of the drawing] end view of the Pivoting Crank on the First Axis driving the Short Eccentric Ratchet Wheel.

This drawing should be read in conjunction with drawings [U7] and [K11].

Reference: [K 45] to [K 57] Missing

Reference: [K 58] Loose

Size: 38 7/8" x 25 3/4"

Caption: Framing plates and details of rejected plans. 14th September 1831.

Watermark: None

Condition: V. dirty: oil marks, grease spots and frayed edges. Centres of wheels have been pierced using dividers or compass points.

Notes:

This drawing contains the details for some parts of the Calculating Part of DE1. Apart from the figure of a plan view over two calculating cells on the bottom, left hand side of the drawing, and the Carrying Lever with its claw on the middle of the right hand side of the drawing, the other parts remain unidentified.

Note this drawing shows details for an early version of DE1, compare the differences in these on this drawing with those on [K40] and [U4]; e.g. note the hair springs controlling the Carrying Lever and the cylinder springs used later for the same purpose.

Reference: [K 59] to [K 61] Missing

Reference: [K 62] Loose

Size: 25 3/4" x 39 5/8"

Caption: Calculating Machine, Elevation of figure wheel framing, and calc wheels, section of bolt.

Watermark: None

Condition: Torn edges, some pencilling. Dirty with oil marks and grease spots.

Notes:

This drawing contains a side and end view of the elevation of DE1. It appears to refer to an early version of DE1.

Reference: [K 63] to [K 70] Missing

Reference: [K 71] Folder 2

Size: 30 1/4" x 51 3/4"

Caption: No caption

Watermark: None

Condition:

Notes:

Drawing comprises details (end view and section) of the Frame which spans the printing end of the DE1 and which supports various shafts e.g. the 60 Wheel Axis, the Ratchet Wheel Axis (Motion from Line to Line), and Crank Axis (motion from line to line). It is clearly shown bolted to the General Platform of DE1.

Drawing shows marking out levels for the following axes (beginning at the rear side of the Engine):

i) Ratchet wheel axis motion from figure to figure

ii) Shade belonging to motion from figure to figure [fulcrum of]

iii) 60 stud wheel axis

iv) First Axis

v) The height above the General Platform of the centre of the Endless Screw Wheel upon the Long Pinion Axis [for line to line motion] is shown with a note: "The Red Line is the true, extreme line.". [See [U7] for plan view of this wheel; this component should not be confused with the Endless Screw Wheel for Figure to Figure Motion].

vi) Centre of Machine

vii) Centre of Frame

viii) Ratchet Wheel Axis motion from line to line

ix) Crank Axis Motion from Line to Line

Other notes on drawing:

Next to bolt No.1 "To the carriage of the spindle for driving returning crank &c."

Next to bolt No.3 "To fixed copper frame"

Next to bolt No.6 "To carriage of returning crank &c."

Next to bolt No.4 "To carriage of returning crank &c."

Next to bolt No.5 "No. 5 reaches from a to b [as shown]"

In middle of top view of frame about the dimension between the two frames: "To be made wider 1832".

Reference: [K 75] Folder 2

Size: 26 1/8" x 39 1/8"

Caption: No caption

Watermark: J. Whatman 182[8?]

Condition:

Notes:

This drawing appears to be a detailed drawing of an early version of the Returning Crank. Shown on the right hand side of the drawing is an end view of the Crank Arm and Wheel which drives it. On the left hand side is a plan view of the pinions which drive it. There are differences between the number of teeth shown on the wheels in this drawing from those shown in [K 86], which is in agreement with those indicated in [U11].

Reference: [K 76] Missing

Reference: [K 77] Folder 2

Size: 24 3/4" x 38 1/2"

Caption: No caption

Watermark: J. Whatman 1828

Condition: Dirty

Notes:

Drawings of the Pinion (overall 50 teeth) on the First Axis driving the Great Wheel (overall 80 teeth) in end-view and section. Shows sets of stepped, starting teeth on both wheels. Two turns of the First Axis are required for one whole turn of the Great Wheel. Note the two locking positions on the Great Wheel and the sprung Roller Lever which locks it. Note the starting teeth on the Pinion slide horizontally about an inch along the First Axis in and out of position, and that the Great Wheel cannot be moved by the Pinion when they are out of contact with those on the Great Wheel. Note the missing teeth on the Great Wheel.

Also some unidentified accounts scribbled on drawing

Reference: [K 78] Folder 2

Size: 25 3/8" x 38 7/8"

Caption: End views of general platform. Plan of framing plates next type sector &c. &c. superimposed.

Watermark: J. Whatman [1830s? not legible]

Condition: Dirty

Notes:

No date. End view of the lower part of the printing end for an early version of DE1. Cf with [K1], [K31] and [K78]. Shows some control wheels (20-Wheel Axis? and Lower 20-Wheel Axis? each has either 12 or 20 teeth etc. on it) and a section through one the main columns supporting DE1. The framing plate superimposed on the drawing in plan view.

Reference: [K 79] Loose

Size: 25 1/2" x 39 1/2"

Caption: End view of general platform and framing plate. 16th May 1832.

Watermark: J. Whatman 182[8?]

Condition: Dirty: oil marks, grease spots and frayed edges.

A similar drawing to [K 78] but not showing the control wheels.

Reference: [K 80] Folder 2

Size: 25 1/2" x 37 3/4"

Caption: No caption

Watermark: None

Condition: Dirty

Notes:

No date. Unidentified parts of DE1 (various components for driving the calculating part of DE1?). Among the figures are various plumbing blocks and bevel wheels, including a double-ended one with 50 teeth.

Notes on drawing:

Next to one of the wheels: "There had better be two recesses for the roller to drop into as the vertical axes may be put out at the end of ½ turn"

Some parts are indicated as "not wanted".

Reference: [K 81] Folder 2

Size: 25 1/2" x 38 3/4"

Caption: No caption

Watermark: J. Whatman 1828

Condition: Very dirty

Notes:

Drawing consists of detailed figures together with numbers to be made of each of various Roller Levers which deal with the lifting and lowering (in/out of gear) of the Pin Clutches located at the bases of the various Vertical Axes in the Calculating Dept of DE1. Also shown are their Springs and support carriages. Compare details with [U4]

Among the many notes made on the drawing include the following:

"One roller lever &c. 48 Wheel"

"One roller lever the carrying axis"

"[?] roller lever the bol. axis"

"2 carriages for lever of intermediate axes

"4 carriages complete and one ... dotted line for Levers of Carrying and intermediate axes."

"The holes drawn to be used at one end of the fulcrum and the [bolts] at the other."

"Two carriages for lever of boltg axes"

"13 spring cases ... withdrawing ..."

"For ... of 48-Wheels"

"Levers of Carrying Axes"

Reference: [K 82] Folder: 2

Size: 25 3/4" x 38 5/8"

Caption: No caption

Watermark: J. Whatman 1828

Condition:

Notes:

Drawing comprises details of the 48-Wheels. Only one set of the driver and driven wheel has been drawn, though DE1 was to have had two identical, connected sets of 48-Wheels. See origin of motion chart, [U11].

Note the movable teeth on the driving 48-Wheel. These can be retracted in or turned into an outward active position.

Note the driving 48-Wheel has half square/half saw teeth. See [U ?].

Also shown on the same drawing are the detailed designs of various Mitre/Bevel Wheels (for driving the Vertical Carrying Axes and Bolting Axes), Plumbing Blocks, Framing Bolts (short).

Note the single locking position on the Locking Wheel fitted to the Vertical Carrying Axis' Mitre Wheel.

Notes on drawing:

Referring to the sockets for the Short Framing Bolts: "One with Boss B and three without it".

Also shown on diagram numbers of various parts to have been made: "4" of the Pillar Sockets. "4" of the Short Framing Bolts. Referring to the brackets and plumbing blocks: "4 for the 1/3 inch neck and one for the 3/4 in neck".

Reference: [K 83] Folder: 2

Size: 25 1/4" x 38 3/4"

Caption: No caption

Watermark: J. Whatman 182[8?]

Condition:

Notes:

No date. Drawing comprises details (section, side view and sketch) of an unidentified wheel with a sprung claw for a ratchet wheel and a pivot. (Part for the early version of DE1?).

Reference: [K 84] Folder: 3

Size: 25 1/2" x 37 5/8"

Caption: No caption

Watermark: J. Whatman 1827 [v. faint]

Condition: Drawing is in parts very faint.

Notes:

No date. Drawing comprises details (plan, side view etc.) of the Intermediate Wheels and Axes used to transfer results from one axis to another during difference calculations involving feedback functions.

Reference: [K 85] Folder: 3

Size: 25" x 37 5/8"

Caption: No caption

Watermark: J. Whatman Turkey Mill 1824

Condition:

Notes:

¼ scale outline plan and elevation of the main structural framing of DE1. Note central location of the punching apparatus and the location of the frame which carries the copper plate [measurements indicate Babbage allowed ca 15 inches for the length of the page (in line to line motion in the direction back to front of DE1) and ca 9 inches breadth of movement across the page (in Fig to Fig or Returning Motion) along the main longitudinal axis of the Engine]. Note the castors upon which DE1 rides are not shown on this drawing.

This drawing would have probably been used by Babbage and Clement to organise the rest of the layout of the machinery in DE1.

It seems that a sheet from an old stock of paper has been used to draw this design on. Query the watermark for the design drawn on it seems to be for the later (1832/33) version of DE1.

Reference: [K 86] Folder 3

Size: 25 5/16" x 38 3/4"

Caption: No caption

Watermark: J. Whatman 1828

Condition:

Notes

No date. Drawing is of the 60-Wheel group of mechanisms in side view and section showing details of the teeth, studs etc.

On the left hand side of the drawing is the 20-Axis in section. On it are shown the tooth for driving the 1st 60-Wheel (with note: "to be made to receive a 2d arm"), the 1st Communicating Wheel, and the 2nd Communicating Wheel, which drives the 2nd 60-Wheel loose on the 60 Axis.

In the middle of the drawing (in section is the 60-Axis with its wheels. Looking at the 3 wheels from bottom to top of the drawing: The first is the 1st 60-Wheel which has movable teeth. This is fixed on the 60-Axis. It has crown/transverse studs on both sides for controlling levers which put the Returning and Zig-Zag Cranks in and out of gear. The second wheel is the 2nd 60-Wheel, which has 60 crown/transverse studs for controlling the levers which operate the shade for the line to line ratchet wheel. This is loose on the Axis. The third wheel is the 3rd 60-Wheel fixed on the 60-Axis. It has spur studs which put the movable part of the 2nd SineQuaNon Wheel (see drawing [K44]) in and out of gear, and also similarly the Sector Wheel on the 20-Axis movable part. On it is written two notes: "This wheel to be left as strong as the casting will admit of" and "It will be necessary to alter this stud wheel or the levers on which it acts or both". The direction of DE1's driving handle is towards the bottom of this drawing.

On the extreme right hand side of the drawing are 2 side views of the 1st 60-Wheel and 1 of the 2nd 60-Wheel. The levers/fingers which put the Cranks in/out of gear are shown acting on the studs on the two sides of the 1st 60-Wheel. Note also that they are also connected to a Roller running round the eccentric edge of one of the SineQuaNon wheels. Shown also in side view is the manner in which the 1st 60-Wheel drives the 2nd 60-Wheel via the communicating Wheels, one which has 21 teeth driven by 60 teeth on the 1st 60-Wheel, the other has 84 teeth driving the 2nd 60-Wheel which has 240 teeth. Note the shape of the teeth on the 1st communicating wheel, half square/half saw.

There is also a side view of the Sine Qua Non Wheel with a note "To be divided and figured on the edge".

Reference: [K 87] Loose

Size: 39 5/8" x 25 5/8"

Caption: End view of printing part, frame and castor

Watermark: J. Whatman 1826

Condition: Relatively clean, torn edges

Notes:

No date. Drawing comprises details (elevation, plan, section etc.) for the two types of castor upon which DE1 was to ride. There is also a sketch drawing of the framing of DE1 in pencil.

Reference: [K 88] Folder 3

Size: 35 3/16" x 39 1/2"

Caption: Old 24 wheel and sectors &c. &c.

Watermark: J. Whatman Turkey Mill 1824

Condition: Damaged and dirty

Notes:

No date. Drawing shows details (end view and section) of the three sets of the movable sector wheels which could be screwed to the 24-Wheel on the early version of DE1. These were used when the 24-Wheel needed to be returned in fast-forward motion to its initial orientation upon completion of the punching of a whole result.

Reference: [K 89] Folder 3

Size: 25 1/4" x 38 1/4"

Caption: No caption

Watermark: J. Whatman 18[??] [too faint]

Condition: Relatively clean

Notes:

No date. Drawing comprises details (plan and end view) of the drive for the Returning and Zig-Zag Motion Cranks.

Beginning on the right hand side of the drawing there is a plan view of the First Axis with two bevel wheels (each with 36 teeth) on it, one held out of gear by means of a screw. The direction of driving handle of DE1 is towards the bottom of the drawing. Next to these bevel wheels is written "Before the groove for the tongue is cut in either of these bevil pinions care must be taken that it is fixed in the right place to bring the spur wheels in contact with the clutches at the proper time".

These bevel wheels engage one of two bevel wheels on the left. One has 72 teeth, the other 108 teeth. They drive a shaft at right angles to the First Axis which has a Spur Pinion on it with 54 teeth. This is turn drives two other wheels each with 72 teeth, one for driving the Returning Crank Axis (at the top of the drawing) and the other the Zig-Zag Motion Crank Axis (at the bottom of the drawing).

Clearly shown are the two clutches which can slide horizontally along each of their shafts in and out of gear with these wheels. Arms on the bosses of these for the levers which perform this action are shown.

On the Returning Crank Axis is another Bevel Wheel (44 teeth) which drives another Bevel Wheel (44 teeth) at right angles to the Returning Crank Axis. This is the Axis of the Crank for Moving from Line to Line. This leads off the top of the drawing.

Adjacent to the Zig-Zag Crank is the following note: "Care must be taken to fix the clutch on this axis at the same angular distance from the arms of the spur wheel as the clutch upon the axis of the returning crank is from its spur wheel when both cranks are in the position in which they rest. To secure this the clutch must not be fixed until the teeth of the wheels are cut."

On the left hand side of the drawing is the above shown in side view.

Reference: [K 90] Folder 3

Size: 25 3/16" x 38 3/4"

Caption: Clutch for ZigZag motion [Crank]. Also some framing pieces.

Watermark: J. Whatman 1826

Condition: Relatively clean.

Notes:

No date. Detailed drawing (plan and side view) of the ZigZag Motion Crank. And of two brackets which presumably support its axis above the surface of the General Platform of DE1.

Reference: [K 91] Missing

Reference: [K 92] Folder 3

Size: 25 9/16" x 39"

Caption: No caption

Watermark: J. Whatman 1828

Condition:

Notes:

No date. End view (viewed from the calculating end of DE1) of the frame and arch which supports the General Platform in the middle of the Engine. Note the two small additional columns underneath the engine which give rigidity and support to the General Platform. Note one has an elongated hole in it to allow horizontal axes to pass through.

Various marking out levels are given. They are the following (from the right hand side of the drawing or front of engine):

Level Distance

i) Studs 0"

ii) Barrel Axis 2.625"

iii) 3 Fig motion 4.8125"

iv) Spiral Axis 6.1875"

v) Carrying Axes and 10.2"

Long Framing Bolts

vi) Centre of the Arch 13.95"

and Machine

vii) Short framing bolts 16.7"

viii) Bolting Axes 19.23"

ix) Columns-columns 22.2"

x) Barrels-barrels 28.8"

xi) Studs 31.4"

Reference: [K 93] Missing

Reference: [K 94] Loose

Size: 39 11/16" x 25 3/4"

Caption: Sine-qua-non wheel for 3 fig motion.

Watermark: J. Whatman 1832

Condition: Relatively clean, torn edges.

Notes:

No date. This is a drawing of the Sine-Qua-Non Wheel for 3 figure motion. Note how its eccentric surface is increased by a lever which slides a movable part into place.

Note that normal eccentric surface applies to figures decimal places 5 to 18 whereas the extended applies to decimal places 1 to 4.

Drawing shows front and back views of the SQN Wheel.

The Roller lever acting on the circumference of the SQN Wheel turns on the 20-Axis.

Note the detent for releasing the Roller Lever.

Reference: [K100] Identified as [K11]. [U7] is a copy.

Reference: [K101] Marked as [U4]

Reference: [K102]

Reference: [K103] Marked as [U6]

Reference: [K104] Marked as [U3[b]]

THE U SERIES

Reference: [U 1[a]] Loose

Size: 36 7/8" x 23 5/8" Trimmed

Caption: Plan and Side Elevation of Difference Engine 1830 [in pencil: ¼ scale]

Watermark: J Whatman 1841

Condition: Relatively clean

Notes:

Also labelled: "197 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines, (Spon, London 1889) by H.P. Babbage.

Drawing is a copy of [U 1[a]], but with less detail shown. The main difference between the two is that a figure wheel has been drawn in each cage on this drawing, but not on the other.

Reference: [U 1[b]] Loose

Size:

Caption: No caption

Watermark: None

Condition: Paper greying.

Also labelled as "199 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines (Spon, London 1889) by H.P. Babbage.

Drawing is 1/4 scale of the Side Elevation and Plan of the Difference Engine of which [U 1[a]] is a copy. Shows more detail than [U 1[a]]. This is a drawing of an early version of DE1.

Measurements taken from the drawing:

That the length of DE1's chassis is 55.99 cms (true size 88.17").

That the length of the Calculating Part (centre of left hand end column to centre of the central column) on the drawing is 22.64 cms (true size 35.65").

That the length of the Printing Part (centre of right hand end column to centre of the central column) on the drawing is 27.20 cms (true size 42.83").

That the height of the Printing Part (from ground to top of support column) on the drawing is 28.45 cms (true size 44.80").

That the height of the General Platform (from ground to top surface of General Platform) on the drawing is 13.80 cms (true size 21.73").

That the height of the Upper Platform (from top surface of the General Platform to top surface of the Upper Platform) on the drawing is 4.14 cms (true size 6.52").

Reference: [U 2[a]] Loose

Size: 24 3/8" x 36 3/8" Trimmed

Caption: End Elevations of the Difference Engine 1830

Watermark: J. Whatman 1841

Condition: Relatively clean

Notes:

Also labelled "198 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines (Spon, London 1889) by H.P. Babbage.

Drawing is a copy of [U 2[b]], but shows less detail.

Scale of Drawing: ¼.

Reference: [U 2[b]] Loose

Size: 22 3/4" x 37 1/2" Trimmed

Caption: No caption

Watermark: None

Condition: Paper greying. Torn and edge torn.

Notes:

Also labelled as "198 Duplicate H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix to Babbage's Calculating Engines (Spon, London 1889) by H.P. Babbage.

Drawing is of the end elevations of the early version of DE1. Scale: ¼.

Measurements taken from drawing:

Width of DE1 (Centre of back side columns to centre of front side columns) 15.595 cms (true size 24.56").

Width of DE1 (Centre of punch support columns (outer columns) back side to front side) 21.21 cms (true size 33.40").

Height of Calculating Part of DE1 (Ground level to top of Columns) 62.42 cms (true size 98.30").

Reference: [U 3[a]] Loose

Size: 38 1/2" x 24 1/2"

Caption: Copy of Drawing of End Elevation of the Lower Portion of the Calculating Part of Difference Engine. March 1833.

Watermark: J Whatman 1831

Condition: Relatively clean

Notes:

Also labelled "198 H.P. Babbage". See list of drawings beginning on p. 288 in the Appendix of Babbage's Calculating Engines (Spon, London 1889 by H.P. Babbage.

Drawing is a vertical section through calculating end of DE1.

Measurements taken from drawing:

Centre of Back Columns to Front Side Columns: 31.25".

Pitch diameter of that 48-Wheel which drives the 48-Wheel on the Axis on which the Barrels turn: 11.77 ins.

Pitch diameter of that 48-Wheel on the Axis on which the Barrels turn: 11.725 ins.

Outer radius of Barrel (centre of barrel to surface of stud) 4.17 ins.

Inner radius of Barrel (centre of barrel to surface of drum (in absence of stud)) 3.90 ins.

Upper surface of General Platform to upper surface of Upper Platform 7.24 ins.

Pitch diameter of Wheel on Great Axis which drives Wheel on Horizontal Carrying Axis 9.65 ins.

Pitch diameter of Wheel on Great Axis which drives Wheel on Horizontal Bolting Axis 6.08 ins.

Pitch diameter of Wheel on Great Axis which drives Wheel on Horizontal Calculating Axis 6.08 ins.

Pitch diameter of Wheel on Horizontal Bolting Axis 6.04 ins.

Pitch diameter of Wheel on Horizontal Calculating Axis 6.12 ins.

Height of centre of First Axis above General Platform 2.80 ins.

Diameter of First Axis 1.36 ins.

Centre of Barrels at rear of Engine to Centre of Barrels on front side 24.16 ins.

Centre of Horizontal Bolting Axis below top surface of General Platform 1.76 ins.

Centre of Horizontal Calculating Axis below top surface of General Platform 1.76 ins.

Centre of Great Axis below top surface of General Platform 7.27 ins.

Centre of Horizontal Carrying Axis below top surface of General Platform 3.84 ins.

Distance of centre of Great Axis from centre of First Axis (which is in the central plane of DE1) 10.79 ins.

Reference: [U 3[b]] Loose

Size: 24 3/4" x 39 1/16"

Caption: None

Watermark: J Whatman 1826

Condition: Dirty. Centre of some wheels patched with small pieces of paper.

Notes:

The original of [U 3[a]]. Almost the same. Main difference is that the centre of the First Axis is drawn as displaced 2 1/8" to the rear of DE1 and 1/2" lower than on [U 3[a]].

Notes on drawing:

Horizontal Bolting Axis "to be 1 inch diam.".

Horizontal Carrying Axis "to be 7/8 [inch diam.]".

On the shoe or stud at the foot of the Vertical Bolting Axis on which it rotates "to be the same size as those on the Caln Axis".

On the shoe or stud at the foot of the Vertical Calculating Axis on which it rotates "to be the same size as those on the Bolting Axis".

On the Roller Lever which runs round the surface of a front side Barrel "Mem[orand]a: All these levers to be made stronger".

Both [U3[a]] and [U3[b]] show an unidentified oblique axis (Communicating Axis?) running underneath the machine connecting (by means of a shaft and bevel wheels) the front side the Spiral Axis to the Horizontal Bolting Axis (or Eccentrics Axis's Mitre Wheel??) on the rear side of DE1. The 2 drawings of this Oblique Axis show a small difference in design of this component; one has more bevel wheels than the other.

Reference: [U 4] Loose in plan press

Caption: Plan of Difference Engine [Calculating Part] 1823-33

Size: 52 2/5" x 40"

Watermark: None

Condition: Torn and Mended

Measurements taken from drawing:

Distance between centre of Columns on front side of Engine 35.89 ins

Distance between centre of Columns front to back side of Engine 33.84 ins?

4 colours of ink used.

This is an important drawing.

Reference: [U 5[a]] Loose in plan press

Caption: Difference Engine 1823-1833

Size: 53 1/10" x 38 3/5"

Watermark: None

Notes:

This is a drawing of the an end-view taken from the calculating end of the Difference Engine.

Measurements taken from drawing

Distance of centre of First Axis to centre of 20-Axis = 6.04 ins.

Distance of centre of 20-Axis to centre of Lower 20-Axis = 2.83 ins.

Distance of centre of First Axis to centre of Great Axis = 10.87 ins.

Distance of centre of Great Axis to centre of Horizontal Calculating Axis = 6.20 ins.

Distance of centre of 20-Axis to centre of 60-Axis = 13.27 ins.

Reference: [U 5[b]] Loose in plan press

Caption: None

Size: 62 1/2" x 41" (trimmed in modern times)

Condition: Poor. Some mould spots.

Watermark: None

Notes:

Incorrectly labelled as [U6] as drawing is very similar to [U 5[a]]. Made up of two sheets joined together.

Reference: [U 6] Loose

Caption: None

Size: 26 1/2" x 25 3/4" (trimmed in modern times)

Watermark: J ... (trimmed off)

Notes:

Is a diagram of a vertical section through the Calculating Part of DE1 viewed from the calculating end of the Engine. Shows clearly in end-view the horizontal driving axes of the Calculating Part of DE1 and the Pin Clutches which drive the Vertical Bolting, Calculating and Carrying Axes. Also shows the manner in which the Barrels front and backside of the Engine and the Roller Levers which act upon them to put the Vertical Axes in and out of gear.

Reference: [U 7] Loose in plan press

Caption: Difference Engine 1823 to 1833

Size: 94 1/4" x 45 2/5"

Watermark: None

Condition: Has torn edges. Made up of two sheets of paper joined together.

Notes:

Drawing is a plan view over the printing/driving/control end of DE1, cf also [K11]. Is a layout of all the components in this part of the Engine. Taken together with [U4] this is probably the most important of the drawings of DE1 to have survived.

Reference: [U 10/1] and [U 10/2] Loose

Caption: None

Size: 25 9/16" x 19 3/16" and 25 1/4" x 20"

Watermark: None and JR 182[3?]

Condition: Torn edge, folded, in part mouldy with grease spots.

Notes:

ff 2. Incomplete mechanical notation for an early version (ca 1826) of DE1, possibly the first draft of a mechanical notation for DE1 Babbage ever drew up. Should be read in conjunction and compared with drawings [U 1[a]], [U 1[b]], [U 2[a]] and [U 2[b]].

In ink, amendments in pencil

Verso on f2 of Notation: outline of a spanner and a lever and a small incomplete timing chart of various parts of DE1's Printing Department.

Reference: [U 11] Loose

Caption: None

Size: 91 1/2" X 47"

Watermark: [Not searched for as chart too large]

Notes:

Complete mechanical notation chart for DE1 dated (in pencil) September or October 1834. Shows details for 228 parts: their names, no. of teeth in each wheel, the number of turns of the First Axis required for one complete revolution of the part concerned, chart of the Origin of Motion (trains), and timing chart showing details of the motion of each part for 3 result cycles (2 of 6 Turns of the First Axis and one of 10 Turns of the First Axis) representing the penultimate, ultimate and first result cycles on a line in the table being produced.

Reference: [U 12] Loose

Caption: None

Size: 21 3/8" x 14 1/2"

Watermark: J Whatman 1823

Notes:

Mechanical Notation Timing Charts of

(1) The operations of carriage of tens by succession (in red ink)

(2) Calculation sub-cycle (in red ink) drawn specially to show the times of locking and unlocking of the lower calculating wheels dated 26 Sep 1831. Note Calcⁿ = 4 turns of [First] Axis. Actions shown: Bolt, Half-Turn, Add and Carrying interspersed with the locking/unlocking of the Lower Calculating Wheels.

(3) A chart of options for the calculation cycles in DE1 (in pencil), i.e. settings for the barrels .

Reproduced on Microfilm B27 reel n.

Reference: [U 13] Loose

Size: 21 3/8" x 29 1/4"

Watermark: J Whatman 1823 with design

Notes:

Mechanical Notation Timing Chart in pencil of the motions of the following parts of DE1:

20-Wheel, Spiral Axis (vertical and circular motions), Crank for returning Copper Frame, First 60-Wheel, Second 60-Wheel, Third 60-Wheel, 20 Axis SineQuaNon Wheel for withdrawing Clutch of Returning Crank, First Axis, Great Axis, 20 or Printing Axis, 48-Wheel Axis, Carrying [Axis of] Table, Type Sector, Snail Wheel, Lower Calculating Wheel of 1st Difference Axis and Carrying [Axis] of 1st Difference. Details of the movement of each part for each tenth of turn of the First Axis for 14 turns of the First Axis are shown. Seems to be a chart of the operations of DE1 upon which a single column of 3 digits is being calculated and punched [Punching of the arguments of a table?]

Also (upside down) a small incomplete chart of the cycle of operations (Add, Carry, Half-Turn, Bolting/Locking) in the calculation sub-cycle for 6th, 5th ... 1st and Table Axes, also charted for 14 turns of the First Axis.

Reference: [U 20] Loose

Caption: None

Size: 24 3/4" x 20 1/16"

Watermark: Mould M...

Notes:

Printed broadsheet or poster version of Benjamin Herschel Babbage's pamphlet Babbage's Calculating Machine, 28th September 1872 on how to operate the 1832 fragment of or model Difference Engine. Reproduced on Microfilm B27 reel o.

Reference: [U 21/1] and [U 21/2] Loose

Caption: [See below]

Size: 15" x 9 4/10" (when folded)

Watermark: None

Notes:

Two folded sheets of lined paper upon which in a 'copperplate' hand copied extracts in French of M. Prony's paper on the production of his tables, Sur les grandes tables logarithmiques et trigonometriques, adaptées au nouveau système métrique décimal séance de l'Académie Royale des Sciences [de France] du 7 Juin 1824. Reproduced on Microfilm B27 reel n.

Babbage's Quarto Scribbling or Sketch Books

BAB [S14]

Q.S.B. Vol 12*: Mislabelled on cover as "List of parts before Aug 1821". Contains notes and description of Difference Engine No. 1 ca May 1830 to January 1831.

Front end of book in ink: Incomplete description by Babbage of the calculating part of DE1.

Back end of book in pencil: Rough notes and sketches by Babbage of the printing part of DE1.

Reproduced on Microfiche D15 1-2:

BAB [S16]

Q.S.B. Vol 16: Babbage's so-called Great Scribbling Book. Material Dates from 1829 onwards. Contains on page stamped with '1801' the original sketch Sept 1834 of the Great Calculating Machine (First version of the Analytical Engine). Contains also Babbage's Address list ca 1829, an inventory of his Dorset Street house. Last date in volume Aug 1853. Includes 17 loose sheets. On Microfilm B27 reel b.

BAB [S17]

Q.S.B. Unnumbered: First page of notes date from 12/9/1865. Labelled Mss on spine. This is probably volume 10 noted Babbage's Calculating Engines page 294 as the one claimed to have been used in Devonshire Street before 1825. Is Babbage's general notebook containing material dated 1825 onwards. Includes 2 loose sheets and a letter from Babbage to a pattern maker April 1836. Also lists of persons who were presented or sent a complimentary copy of the paper on Mechanical Notation, Diving Bell, Decline of Science, Life Assurance and the book of logarithms is inserted in this volume. Contains among other things notes on difference tables of logarithms, the Mechanical Notation, list of persons invited to the meeting of friends held in May 1829 to discuss the calculating machine, some rough costings of work done by Clement to put to the latter-mentioned meeting. On Microfiche D18 1-17.

Field Archives Volume 2 f57:

Amount owing by Charles Babbage to Joseph Clement for work done to his Calculating Engine to 31st December 1831. References each item to cost statements in previous accounts (item costs not given). Balance of account is given (p.19) as £1720-14s-4d with an itemised error in Clement's favour of £4-18s-0d making Babbage's debt £1725-12s-4d. Ie. some pages from the accounts for Babbage's first Difference Engine when Field acted as one of the arbitrators. They are signed 17.7.1832 by Joshua Field and Bryan Donkin.

New Developments for a Difference Engine 1834-1842

Drawings from the Analytical Engine Series [A]

BAB [A]39 12/11/1836

Adding and Circular Carrying for Difference Engine. Wheels numbered 1 to 100

Adding No. 6, Carrying No. 14 Sketch of a method of Adding and Carrying Intended for a Difference Machine Designed between 31/10/1836 and 12/11/1836 [Plan, elevations, details, description].

BAB [A]40 18/11/1836

Circular Carriage no. 5 and Difference Engine

Adding No. 7. Carriage no. 15 Sketch of a Method of Adding and Carrying with Anticipation. Intended for a Difference Machine or an Equation Difference Machine. [Plan, elevation, description] 18/11/1836.

BAB [A]99 1/3/1842

Long Pinions for Giving off Complement

Long Pinions for giving off Complement [Algebraic Addition Sketch Book 3 pp.389, 395] [Plan and Elevation] 1/3/1842

Rough sketch of an element of a Difference Engine and method of carrying consecutively 17/4/1842. (20/5/1842) [Sketch Book 5 p.119] [Plan, elevation and description]

Other Items in the Science Museum

a) Photograph of plan, side elevation and end elevation of Babbage's Difference Engine. INV 1878-4

b) Two packets containing card cutouts of gear-wheels, cams etc for Babbage's Difference Engine No. 1. Presented by King's College, London. Kept in Museum, location S.B53. CU.08.05. INV 1971-266.

Packet I labelled "Models"

In envelope

a) Card cut-out of Great Wheel dated 16th Oct 1831

80 teeth in whole circle (0.473+ Pitch, Radius 6.025-).

b) Card cut-out of Pinion for driving Great Wheel dated 16th Oct 1831. 50 teeth in whole circle (0.473+ Pitch, Radius 3.756+). Last effective tooth indicated.

c) Card cut-out of Pinion for driving Sector of 20-Wheel on Printing Axis. (30 teeth, 4" pitch diameter).

d) Card cut-out of Cam for raising Spiral Axis dated 21 Sep 1832 (Timing: .1 for raising, .1 rest up, lowering .1, .7 rest down. Minimum radius 1 15/16" Maximum radius 2 7/16").

e) Notes and Sketches

i) Levers for moving 20 Teeth from 48 Wheel. Labelled 'Approved'.

ii) Levers for moving Sine-Qua-Non Wheel and Sectors. Labelled 'Approved'. dated 17th Jan 1833.

f) Card cut-out of Bolting Lever

g) Card cut-out of Carry Lever

h) Unidentified card cut-out

i) Rejected plan for Great Wheel and its Starting Teeth, undated.

j) Final plans for the Great Wheel, its Starting Teeth ('Wings') and the Pinion which drives it , dated 19th March 1833.

i) Card cut out of Great Wheel with its Wings (88 teeth in whole circle arranged thus : 5.5 teeth Wing I, 38.5 normal teeth, 5.5 teeth Wing II, 38.5 normal teeth).

ii) Card cut-out of Pinion which drives Great Wheel (55 teeth in whole circle arranged thus : 5.5 stepped teeth, 38.5 normal teeth and 11 cut away. Timing: .1 rest, .2 increase velocity, .7 to complete revolution).

Between cardboard boards

a) Notes on Levers for putting Starting Teeth of Great Wheel in gear. Labelled 'Approved'.

b) Various models or card cut-outs of the 'Wings' of the Great Wheel of the calculating department of the Difference Engine and of the Pinion which drives it.

c) Collection of miscellaneous unidentified parts (19).

d) Scrap card for cut-outs ?

e) Card cut-out models of miscellaneous components

i) Roller Lever

ii) 60-Stud Wheel model of a Stud dated 24th Jan 1832

iii) Bolting Lever

iv) Finger on Bolting Axis

v) 3 Miscellaneous unidentified Gear Wheels

f) Card cut-out models of components for the Printing or 20-Axis department

i) 2 Models of the Single Tooth which drives the 20-Wheel dated Sep ?? [date unreadable].

ii) Model of 20-Wheel.

iii) Model of Locking Wheel and Roller Lever for locking 20-Axis, dated 15th Nov 1831.

iv) Model of a Stud for a Stud Wheel?

g) Card cut-out models of components for the Punching and Spiral Axis departments

i) Cam of Punching Apparatus (Timing: descent of punch .1875, ascent of punch .0625: total .25 of tunr of First Handle).

ii) 2 Cams from printing department.

iii) Arm for raising Spiral Axis, dated 21 Sep 1832.

iv) Roller and Arm for raising Spiral Axis, dated 3rd Sep 1831.

Packet II labelled "Models of Rejected Contrivances"

Between cardboard boards

a) Miscellaneous unidentified components. Some not Difference Engine material (Pendulum experiments?).

b) Card cut-out models of components from Punching department

i) Enlarged Type Sector Cam, dated 16th Jul 1832. (Timing: .3 lowering, .25 rest down, .15 move up, .3 rest up).

ii) Type Sector Cam. (Timing: .3 lowering, .25 rest down, .15 move up, .3 rest up).

iii) Cam for raising Spiral Axis, dated 3rd Sep 1831.

iv) 2 more Type Sector Cams.

v) Type Sector Arm.

c) Card cut-outs of components from the 20 or 24-Wheel (Printing Axis) department

i) Lever for lifting Locking Roller of 20-Wheel, dated 15 Nov 1831

ii) Cam for lifting Locking Roller of 20-Wheel, dated 15 Nov 1831

iii) Pinion and Cam for 24-Wheel, dated Sep 1831. Note by CB "Rejected the 20-Wheel and single tooth of Sepr 19 preferred".

iv) Unidentified component.

v) 24-Wheel, dated Sep 1831. Note by CB "Rejected the 20-Wheel and single tooth of Sepr 19 preferred".

vi) Lever for Shade.

d) Miscellaneous card cut-outs of components from an early (1828) verison of Difference Engine No. 1. Notes on cut-outs not in CB's handwriting. Components unidentified, one dated 10 Jan 1828.

e) 2 miscellaneous components

i) A Snail Wheel

ii) Lever upon which the stud acts to move the Shade of the line to line motion, dated 24 Jan 1832.

f) More card cut-outs or models of the Great Wheel, its starting teeth and the Pinion on the First Axis which drives it.

i) 2 Models of the Great Wheel with 'Wings'.

ii) Rejected plan of Pinion and Starting Teeth for driving Great Wheel

iii) Starting Teeth for Great Wheel, dated 16 Oct 1831

iv) Starting Teeth for Pinion which drives Great Wheel, dated 16 Oct 1831

g) Various models of the Pinion on the First Axis which drives the great Wheel of the calculating department.

Various models of the 'Wings' or Starting teeth of the Great Wheel.

c) 17 Technical Drawings of the replica of the Fragment of the First Difference Engine (1832) drawn by J.W. Harding of Munro Ltd, London N11 in 1957 for IBM. Science Museum Library reference no. M.S.P. 19.

Drg 1 Bolting Arms and Index Arms drawn 1.7.1957

Drg 2 Adding Wheel and Locking Mechanisms drawn 2.1.1957

Drg 3 Bolting and Carrying Mechanisms drawn 15.7.1957

Drg 4 Plan sectional view drawn 28.6.1957

Drg 5 Framing Plates and spacers drawn 19.7.1957

Drg 6 Miscellaneous parts drawn 25.7.1957

Drg 7 Alarm mechanisms drawn 7.8.1957

Drg 8 'Eating one's own tail' Mechanisms drawn 9.8.1957

Drg 9 Plan, side view and elevation view of top and driving mechanisms drawn 10.8.1957

Drg 10 Top Framing Plate drawn 26.8.1957

Drg 11 Driving Gear drawn 6.9.1957

Drg 12 Driving Gears drawn 10.9.1957

Drg 13 Shafts drawn 12.9.1957

Drg 14 Bottom Framing Plate drawn 12.9.1957

Drg 15 Springs and Spring Cases drawn 14.9.1957

Drg 16 Miscellaneous Parts drawn 16.9.1957

Drg 16a Carry Lever Springs drawn 7.1.1957

Total number of parts in replica: 1976

British Library Manuscripts Department,

British Museum, Great Russell Street, London WC1.

Babbage's General Correspondence and Miscellaneous Scientific Papers Additional Manuscripts 37182-37205

This is the British Library's principal collection of Babbage manuscripts. It contains the correspondence with Babbage from many of the famous mathematicians and scientists of the time from both home and abroad, interspersed with the drafts of some of his own letters, as well as a set of the manuscripts of some of his non-calculating engine scientific papers and notes. The collection was deposited by his son, Henry Prévost Babbage, in 1905.

Correspondence Files

Add. Ms. 37182 1806 - Dec 1822 ff 464

Add. Ms. 37183 Jan 1823 - Mar 1827 ff 466

Add. Ms. 37184 Apr 1827 - Dec 1829 ff 480

Add. Ms. 37185 Jan 1830 - Jun 1831 ff 561

Add. Ms. 37186 Jul 1831 - Jun 1832 ff 520

Add. Ms. 37187 Jul 1832 - Jun 1833 ff 569

Add. Ms. 37188 Jul 1833 - Dec 1834 ff 559

Add. Ms. 37189 Jan 1835 - Dec 1836 ff 509

Add. Ms. 37190 Jan 1837 - Sep 1838 ff 578

Add. Ms. 37191 Oct 1838 - Dec 1841 ff 696

Add. Ms. 37192 Jan 1842 - Dec 1843 ff 499

Add. Ms. 37193 Jan 1844 - May 1847 ff 551

Add. Ms. 37194 Jun 1847 - Dec 1851 ff 659

Add. Ms. 37195 Jan 1852 - Sep 1854 ff 570

Add. Ms. 37196 Oct 1854 - Apr 1856 ff 490

Add. Ms. 37197 May 1856 - Mar 1860 ff 507

Add. Ms. 37198 Apr 1860 - Sep 1863 ff 557

Add. Ms. 37199 Oct 1863 - 1899 ff 610

Add. Ms. 37200 Undated: Correspondents A - L ff 513

Add. Ms. 37201 Undated: Correspondents M - Z ff 645

Sir Robert Peel Collection:

Add Ms 40419 f154 Letter from Babbage to Sir Robert Peel, dated 7th April 1835: transmitting to him a copy of the statement he had made to the Duke of Wellington about his Calculating Machine on 23th Dec 1834.

Add Ms 40516 f265 Letter from Babbage to Sir Robert Peel, dated 8th October 1842: requesting the latter to come to a decision about the government's intention on the question of the Difference Engine.

Add Ms 40516 f267 Peel's reply to Babbage on the above, dated 4th November 1842. Passing responsibility to Goulburn to convey their joint views.

Add Ms 40611 f181 Copy of the Statement addressed to the Duke of Wellington dated 23rd December 1834 on the Calculating Machine.

Cambridge University Library

West Road, Cambridge CB3 9DR

Telephone 0223-333000

Cambridge Philosophical Society Archives.

Babbage Collection

Mathematical and Astronomical Tables

ADD 8705 37.

(a) Proof copy (17x10) printed from stereotype plates of part of the great French table made under the direction of Prony. The table was never published. There is a note by Babbage to the effect that this copy was given to him by Didot on his first visit to Paris.

(b) Manuscript of a table of logarithms (15x9.5) with a note by Babbage stating that it was copied from an original Ms at the Observatory of Paris.

(c) A double sheet (15x9.5) containing a fair copy of some series for computing logarithmic differences. The computed differences would be used as settings for the Difference Engine.

ADD 8705 18.

A bundle consisting mainly of correspondence and working papers from the year 1827 relating to the comparisons made by Babbage of logarithmic and trigonometrical tables from various sources. The letters are from Henry Jenkins to Dr Young, from David Booth to Babbage, from Woolgar to Davies Gilbert, and from Davies Gilbert to Babbage. Some of them are quite critical of the design and layout of Babbage's Table of Logarithms. Included also in the bundle are notes on the Errors in Chinese tables; Notes on the Trials of colored paper by candlelight; A sheet dated 14 Dec 1826 of Logarithmic comparisons made by Sergt. James McKay and Private John Strahen Royal Sappers, Ordnance Survey Office, Phoenix Park [Dublin]; and a printed table of Proportional Parts. A single sheet (7.5x6) has noted on it some errors in Taylor's tables. On the back are 'Hints for Travellers'; for example, 'do not be afraid to ask the price of articles and meals'. The bundle includes a bill from the printer for preparing Babbage's table of logarithms, and some correspondence with a bookbinder.

ADD 8705 44.

A copy of the ultimate edition dated 1889 of Babbage's logarithms. It contains Henry P. Babbage's autograph together with details of the financial arrangements made by him with William Clowes, the printer.

ADD 8705 19.

A single sheet (11.5x9.5) containing a note dated 21 March 1858 and initialled by Babbage recording a conversation with Mr Hind, Director of the Nautical Almanac, about Hansen's new lunar tables. They give better results than the previous tables, but the computations take twice as long. Sixty errors, not mentioned in the list of errata, have been discovered.

Machinery

ADD 8705 21.

A single sheet (9x8) headed On a method of expressing the action of machinery. Evidently an introductory paragraph for some projected account.

ADD 8705 22.

A double sheet (15.5x9.5) on one side of which is a notation for division in the Analytical Engine. Also, a single sheet of the same size with a rough notation - apparently also for division- on one side, and some jottings and a couple of rough sketches on the other. A third sheet (16x12.5) has roughly written on it, in pencil, charts illustrating options for the general calculation and printing cycles of Babbage's first difference engine, n.d. watermark 1826.

Notebooks and scribbling books

ADD 8705 23.

A small notebook (8.5x7) Labelled 1825 on front cover and endorsed on the first page 'St Michael's Hill, 29 July 1825' and full of miscellaneous notes on the things that caught Babbage's attention at the time. There is an index at the front. Contains notes on his stay in Paris in 1826, including a visit to Gambey's workshop where those techniques which inspired him were copied down in this notebook. Notebook contains what appear to be sketches of designs for various components of the printing part of Difference Engine No. 1.

ADD 8705 38.

Account book used as a notebook. Much of it is taken up with notes on the rotation of needles by electricity. These have dates 1826 and 1830. Between December 1832 and 1838 the book was used to record calculations made by Babbage using the Fragment Difference Engine (1832), now in the Science Museum. Also contains notes on turning tool edges.

Public Record Office

PRO Kew Division,

Ruskin Avenue, Kew, South West London.

Treasury Department Archives

The following are the papers relating to the development of Babbage's Difference Engine No. 1 to be found in the British Government's Treasury Department's archives.

The following list was compiled from the box of Babbage papers referenced as T1/3428, also known as 'Long Bundle 17', and the Treasury Papers and Letters-In Register T2. Each item in the list below is headed by its year of entry in the T2 Registers and the serial number assigned to it by the then clerks of the Treasury.

The Minute Books of the meetings of the Board of the Treasury are to be found in T29; Out-Letters to the Auditors in T6; Out-Letters General File T27; Out-Letters to the Commissioners of Woods, Forests and Land Revenues in T25.

1823-6158

Copy of the 12 page printed quarto edition of Babbage's letter to Sir Humphry Davy dated 3rd July 1822.

Registered/Received 21st March 1823

Read 25th March 1823

1823-9621

Letter from the Secretary of the Royal Society [Wm. Thos. Brande] to the Treasury dated 1st May 1823 on Mr Babbage's Invention for the purpose of Calculating and Printing Mathematical tables. [Item printed: see Papers of the Parliamentary Session 1823 Accounts and Papers (2) Vol XV page 9 Paper No. 370 -Copies of the Correspondence between the Lords Commissioners of His Majesty's Treasury and the President and Council of the Royal Society, relative to an Invention of Mr Babbage.]

Registered/Received 1st May 1823

1823-15012

Letter from members of the Royal Society respecting Mr Babbage's Invention for constructing numerical tables dated London, 3rd July 1823.

Registered/Received 11th July 1823

Read 11th July 1823

1828-22672

Mr Babbage with a statement and papers respecting his Calculating Machine dated 11th December 1828.

Registered/Received 23 Dec 1828

Read 23 Dec 1828

a) Copy of Babbage's letter to Duke of Wellington, 11th Dec 1828

b) Minute of the Board of Treasury, 23rd Dec 1828

c) Statement (11th Dec 1828) respecting Mr Babbage's Calculating Machine and Of the Utility and Present State of the Calculating Engine.

Enclosures:

A. Parliamentary Paper 1823 No. 370 reprint of Babbage's Letter to Sir Humphry Davy and including the correspondence between the Treasury and the Royal Society, and the Report of the Committee of the Royal Society convened to examine the proposal.

B. Speech of the President of the Astronomical Society, Mr Colebrooke on presenting Babbage with the gold medal of the Society.

C. Offrint of Francis Baily's paper on the Utility of Mr Babbage's Calculating Engine, published as Article LVIII in Phil. Mag. May 1824, pp 355-366. Printed by Richard Taylor, London.

D. Reply as published in the Times 19 Aug 1828 of Mr Herschel to a statement re Babbage's Engine.

d) Tied up in same bundle 3 pages of a foolscap printed paper signed by I.T.W. Herschel Chairman: "Report of the Committee, appointed by the Council of the Royal Society, to consider the subject referred to in Mr. Stewart's Letter, relative to Mr Babbage's Calculating Engine and to report thereon."

1829-2964

Secretary of Royal Society with copy of a report and resolution respecting Mr Babbage's Calculating Engine dated 16th February 1829

Registered/Received 21st February 1829

Read 24th April 1829

a) Letter from P.M. Roget, Secretary of the Royal Society to J. Stewart, 16th Feb 1829.

b) Report of the Committee of the Royal Society Feb 1829

c) Handwritten minute of the Council of the Royal Society 12th Feb 1829.

d) Minute of the Treasury 28th April 1829

e) Babbage to Richard Penn 18th April 1829

Associated papers held in same bundle:

a) 12th May 1829 Opinion of Mr Babbage's Personal Friends respecting the Calculating Machine in Babbage's handwriting.

b) Babbage to Duke of Wellington 13th August 1829

c) Babbage to Henry Goulburn 24th November 1829

d) Babbage to Lord Ashley 25th November 1829

e) Minute of Treasury 24th November 1829 second reading of 2964/1829

1830-21516

A letter from Babbage to the Chancellor of the Exchequer requesting payment of a sum due to him on Account of his Calculating Machine dated 20th December 1830

Registered/Received 21st Dec 1830

Read 21st December 1830

a) Babbage to Chancellor of the Exchequer 21st Dec 1830 together with an Account of Expenditure on the Machine

b) Minute of the Treasury 21st Dec 1830

1830-21785

A letter from Chas. Babbage to the Treasury relative to the expenses of the Calculating Machine invented by him dated 23rd December 1830

Registered/Received 23rd Dec 1830

Read 24th December 1830

a) Babbage to Treasury 23rd December 1830

b) Minute of Treasury 24th December 1830

1830-22144

A letter from the Secretary of the Royal Society acknowledging receipt of a communication relative to Mr Babbage's application for an additional sum of money towards carrying on the construction of his calculating machine dated 27th December 1830.

Registered/Received 30th Dec 1830

Read 31 Dec 1830

a) P.M. Roget Secretary of Royal Society to Treasury 27th Dec 1830

1831-8557

Letter from the Secretary of the Royal Society dated 14th April 1831 enclosing reports of Committee and Council of the Royal Society.

Registered/Received 2nd May 1831

Read 5th July 1831

a) P.M. Roget Secretary of Royal Society to Treasury 14th April 1831

b) Report of Committee of the Royal Society Feb 1829

c) Report of the Council of the Royal Society (printed) Feb 1829

d) Handwritten Report of Committe of Royal Society March 26th 1831.

Associated papers in same bundle:

a) Letter P.M. Roget to Treasury 9th May 1831

b) Letter P.M. Roget to Treasury 22nd June 1831

c) Minute of the Board of Treasury 5th July 1831

1831-8558

Communication from the Commissioners of Wood, etc. with a report relative to the proposed removal of Mr Charles Babbage's Calculating Engine, from Lambeth to Dorset Street [Nr.] Portman Square dated 30th April 1831

Registered/Received 2nd May 1831

Read 3rd May 1831

a) Letter and Report 30th April 1831

b) Minute of Treasury 3rd May 1831

1831-13178

A letter from Babbage to the Treasury with an application for sums advanced by him for works done to his Calculating Machine dated 5th July 1831.

Registered/Received 5th July 1831

Read 12th July 1831

a) Babbage to Lords of the Treasury 5th July 1831

b) Babbage to J. Stewart 5th July 1831

c) Minute of the Treasury 12th July 1831

d) Babbage to Lords of Treasury 18th July 1831 with an account of expenditure of sums issued to him to defray charges for the Calculating Machine.

1831-15302

A letter from P.M. Roget Secretary of the Royal Society to the Treasury on the subject of appointing an engineer to examine Mr Babbage's Calculating Machine dated 29th July 1831.

Registered/Received 3rd August 1831

1831-15310

Communication from the Commissioners of H.M. Woods, etc. with a Report with drawings, in specification, and estimate of cost of proposed arrangement for removal of Mr Babbage's Calculating Engine to Dorset Street Manchester Square dated 29th July 1831.

Registered/Received 3rd August 1831

Read 19th August 1831

Action: Write to Commissioners of Woods, etc. (19th August 1831)

a) Commissioners of Woods report 29th July 1831

b) Minute of Treasury (4th Div) as to purchase of Mr Babbage's premises, 19th August 1831

1831-16283

Mr Speer and Mr Brooksbank (Treasury Auditors) report on the account of Chas. Babbage Esq. in respect of sums issued to him to defray the expenses of the Calculating Engine dated 12th August 1831.

Registered/Received 18th August 1831

Read 26th August 1831

a) Speer and Brooksbank letter 12th August 1831

b) Copies of Babbage's Statement 5th August 1831

c) Speer and Brooksbank's Statement 12th August 1831

d) Letter Praeds and Co. to Babbage dated 4th August 1831 re a draft paid to Clement for £144-9-3 on 2nd April 1830.

e) Note Babbage to Speer and Brooksbank 15th August 1831

f) Report of Committee of Royal Society March 26th 1831

g) Minute of Treasury (6th Div) 26th August 1831.

1831-19114

Babbage to the Treasury for a further issue on account of his calculating machine dated 29th September 1831.

Registered/Received 29th September 1831

Read: 30th September 1831

a) Babbage's Letter to the Treasury 29th September 1831

b) Minute of the Treasury 30th Sept 1831

1831-20002

Commissioners of His Majesty's Woods, Forests and Land Revenues further report relative to the proposed arrangement for the removal of Mr Charles Babbage's Calculating Engine to Dorset Street Manchester Square dated 13th October 1831.

Registered/Received 14th October 1831

Read 25th October 1831 (Sundries, 4th and 6th Div)

a) Report of the Commissioners of Woods, Forests etc. 13th October 1831

b) Minute of Treasury on Buildings for Calculating Engine 25th October 1831

c) Letter Babbage to Lord Althorp 6th January 1831

d) Babbage's Instructions to Jearrad No.1

e) Babbage's Instructions to Jearrad No.2

f) Letter Babbage to Wickham 6th January 1831

g) Chas. Jearrad's Surveys

Report No. 1 Jan 6th 1831

Report No. 2 and abstract of expenditure Jan 15th and 18th 1831

h) Abstract of Expenditure and Rental as according with Report No. 2 [Jearrad Jan 18th 1831]

1832-2503

Surveyor General of Works to Treasury with application from Mr Decimus Burton Architect employed in erecting buildings for reception of Mr Babbage's Calculating Machine for an advance of £1000 dated

Registered/Received 7 February 1832

Read 10th February 1832

a) Letter from the Surveyor General of Works

b) Minute of Treasury 10th February 1832

1832-3720

Charles Babbage to Treasury enclosing Account and Voucher of Sums expended on his Calculating Machine and requesting an issue on account thereof dated 23rd February 1832.

Registered/Received 25th February 1832

a) Babbage's Letter and sundry enclosure 23rd Feby 1832

b) Account (July 1831-December 1831) for £1701-10-5½.

1832-5123

Report of Mr Speer and Mr Brooksbank on the second account [see 3702 above] of Chas. Babbage Esq. in respect of sums issued to him to enable him to proceed in constructing a Calculating Engine dated 10th March 1832

Registered/Received 17th March 1832

Read 27th March 1832

a) Speer and Brooksbank's report and statement of account 10th March 1832

b) Minute of Treasury 27th March 1832

1832-7943

Commissioner of Woods, etc. request for an issue of a further sum [£683-9-0] for the completion of the Building for Mr Babbage's Machine dated 13th April 1832

Registered/Received 25th April 1832

Read 1st May 1832

a) Letter 13th April 1832 Office of Woods to Treasury

b) Minute of Treasury 1st May 1832

c) Copy of D. Burton to Milne 29th March 1832 and 5th April 1832

1832-9546

Mr Babbage further for issue of £1701-10-5½ on account of Calculating Machine, dated 18th May 1832

Registered/Received 18th May 1832

a) Babbage to Treasury 18th May 1832

b) Babbage to J. Stewart 18th May 1832

1832-9862

Treasury Auditors (Speer and Brooksbank) on letter from Mr Babbage requesting further issue of money on account of Calculating Machine dated 23rd May 1832.

Registered/Received 24 May 1832

Read 29th May 1832

a) Speer and Brooksbank to Treasury 23rd May 1832

b) Minute of Treasury 29th May 1832

1832-13451

Babbage to Treasury with copies of the correspondence respecting removal of his calculating machine to premises in East Street dated 14th July 1832 with 4 enclosures. (see 33149)

Registered/Received 16th July 1832

Read 12th September 1832

a) Letter Babbage to Treasury 14th July 1832

b) Letter Babbage to J. Stewart 14th July 1832

c) Letter Clement to Babbage 6th July 1832 Memorandum No.1

d) Letter Clement to Babbage 6th July 1832 Memorandum No.2

e) Copy of Letter Babbage to Clement 18 May 1832

f) Minute of Treasury 12th September 1832

g) An Account of Sums issued on account of Mr Babbage's Calculating Engine [Total expended including Building £14938- 17-6 excluding estimated cost of the building for housing the Calculating Engine £12340-16-6]

h) Particulars of the proposal, or demand made by Mr Clement, the Engineer employed upon Mr Babbage's Engine upon its removal to East Street.

1832-14777

Mr Babbage with Bill for Calculating Machine to 30th June 1832 and requesting issue of that amount of money dated 4th August 1832.

Registered/Received 4th August 1832

a) Babbage to J. Stewart 4th August 1832

1832-16205

Messrs Speer and Brooksbank's report to the Treasury on the account of Mr Chas. Babbage in respect of the sum of £1701- 10-7 paid him by Mr Sargent on the 9th June 1832 on account of the Calculating Engine and relative to the payment of a further claim of £1956-5-11½ for works performed by Mr Clement requested in 14777/32 above to the 30th June 1832. Report dated 20th August 1832.

Registered/Received 23rd August 1832

Read 1st Sept 1832

a) Speer and Brooksbank to Treasury together with a statement of the account dated 20th August 1832

b) Minute of the Board of the Treasury, 23 Augt 1832

1833-6049

Mr Chas. Babbage to Treasury detailing certain difficulties between himself and Mr Clement in regard to the Calculating Machine dated 28th March 1833.

Registered/Received 29 March 1833

a) Babbage to J. Stewart 28th March 1833

b) Copy of Clement to Babbage 26th March 1833

c) Babbage to J. Stewart 28th March 1833 (Letter No.2)

1833-6050

Mr C. Babbage with Mr Clement's Account for the Calculating Engine and requesting an issue for payment thereof dated 28th March 1833

Registered/Received 29th March 1833

a) Babbage to Treasury 28th March 1833

b) Statement of Account to 29th Dec 1832 £1782-11-4¼: examined articles Feby 8th, examined account Feby 20th: signed Donkin and Field.

1833-6570

Commissioners of Woods, etc. to Treasury for an amount to pay the expenses of the erection of the building for Mr Babbage's Calculating Machine [total expended £2452-3-6] dated 4th April 1833.

Registered/Received 4th April 1833

Read 4th April 1833

a) Office of Woods etc (H.H. Seward) to Treasury (A.G. Spearman): Total Amount spent £2190-13-6 or estimated total when complete £2452-3-6 for building works.

b) Minute of Treasury: Commissioners of Woods, etc to repay the sum of £1000 advanced from Civil Contingencies fund, dated 4th April 1833.

1833-9626

Speer and Brooksbank to the Treasury on the Account of Mr C. Babbage in respect of sums on account of the Calculating Engine in respect of the Sum of £1956-5-11 paid to him by Mr Sargent on the 20th September 1832 and on the subject of a further Bill of £1782-11-4 for works performed by Mr Clement for the Engine to 31st Dec 1832, dated 7th May 1833. [See 1833-6050].

Registered 17th May 1833

Read 24 May 1833 and 13th August 1833

a) Speer and Brooksbank to Treasury 7th May 1833 with a statement of the Account.

1833-9883

Mr Babbage Esq. requests that future issues on account of Calculating Machine may not pass thro' his hands dated 20th May 1833. See 1833-9626.

Registered/Received 21st May 1833

Read 24th May 1833 and 30th August 1833

a) Babbage to J. Stewart 20th May 1833

b) Copy of Letter Clement to Babbage 13th May 1833

c) Minute of Treasury 24th May 1833

d) Babbage to J. Stewart 20th May 1833 (2nd Letter)

1833-14368

Mr Joseph Clement's proposals for continuing work on Mr Babbage's Calculating Machine and for payment of his accounts dated 22nd July 1833.

Registered/Received 23rd July 1833

Read 13th August 1833

a) Clement to the Lords Commissioners of the Treasury, 22nd July 1833.

1833-14836

Mr Babbage regarding the removal of the drawings and finished parts of the Calculating Engine into the fire proof house dated 29th July 1829.

Registered/Received 30th July 1833

Read 13th August 1833

a) Copy of Letter Clement to Babbage 22nd July 1833

b) Babbage to Treasury 29th July 1833

c) Babbage to Stewart 29th July 1833

1834-2043

Joseph Clement requesting that some measures be adopted for the Examination of his accounts in regard to the Calculating Machine, and for a settlement of his claim, dated 30 January 1834.

Registered/Received 30th January 1834

Read 4 February 1834

a) Clement to Treasury 30th January 1834

b) Minute of Treasury 4th Feb 1834

1834-13850

Mr Babbage apprizing the Board [of Treasury] of the Drawings etc. of the Calculating Machine having been all deposited in the fire proof building and requesting instructions as to the further progress thereof, dated 16th July 1834.

Registered/Received 17th July 1834

Read 18th July 1834 and again 12th Aug 1834

a) Babbage to Treasury 16th July 1834

1834-14831

Mr J. Clement enclosing his account for work done to the Calculating Machine to the 12th March 1833, dated 29 July 1834.

Registered/Received 30th July 1834

a) Clement to Treasury 29th July 1834

b) Statement of Account to 12th March 1834 [1833] signed Bryan Donkin and Joshua Field 13 June 1834 £1200-13-6½

1834-14932

Mr Clement that the Expense of removing the Calculating Engine to the Fire Proof Building in East Street amounts to £156-16-2, dated 31st July 1834.

Registered/Received 1 August 1834

Read 4th August 1834

a) Clement to Treasury about Removal Costs of £156-16s-2d included in account above dated 31st July 1384

1834-15159

Mr Speer with a report on Mr Clement's Bill for works performed to the Calculating Machine subsequent to the termination of the year 1832 and for the expense of its removal to East Street amounting together to £1200-13s-6½d. See 13850, 14831, 14932. Dated 4th August 1834.

Registered 5th August 1834

Read 12th August 1834

a) Speer to Treasury 4th August 1834

b) Minute of the Treasury 12th August 1834

1835-20447

Commissioner of Woods Etc. Estimate of the Sum requested for certain repairs of the Building erected for Mr Babbage's Machine, dated 17th October 1835

Registered/Received 19th October 1835

Read 13th November 1835

a) Commissioners of Woods and Forests to Treasury 17th October 1835

b) Copy of letter from Decimus Burton 5th October 1835 to Henry Hake Seward of the Office of Woods etc.

1842-16942

Letter from Babbage to Treasury

Registered/Received Friday 19 August 1842

Assigned Sir G. Clerk

Archives of the Surveyor General of Works

Current File Reference: WORK 12-62/8

Is contained in two folders: ff 1-40 and 41-68

[Maps and Plans of the Building intended to house the Difference Engine have gone missing].

Files Contain copies of the following letters and reports.

Folder 1 ff 1-40:

Babbage to D. Burton 19th April 1831

D. Burton to Milne of the Office of Woods 21st April 1831

Office of Woods to Treasury 30th April 1831

Treasury to Office of Woods 6th May 1831

Office of Woods to D. Burton 20th May 1831

D. Burton to Milne of the Office of Woods 1st July 1831

Copy of Letter Babbage to D. Burton 19th April 1831

Babbage to D. Burton 1st July 1831

D. Burton's Specification for the Building 1st July 1831

Milne to D. Burton 12th July 1831

Burton to Milne 14th July 1831

Babbage to D. Burton 14th July 1831

Office of Woods to Treasury 29th July 1831

Treasury to Office of Woods 19th August 1831

Milne to Burton 12th September 1831

Burton to Milne 24th September 1831 with statement of the separate expenses of construction the different buildings required.

Babbage to D. Burton 16th September 1831

Office of Woods to Treasury 13th October containg Babbage's reasons for making the workshops a permanent erection dated 31st August 1831.

Another Letter Office of Woods to Treasury dated 13th October 1831.

Folder 2 ff 41-68:

Treasury to Surveyor General 31st October 1831

Treasury to Commissioners of Woods 31st October 1831

Office of Woods to Major General Stephenson 15 Nov 1831

William and Lewis Cubitt (Grays Inn Road) to Stephenson 30th November 1831 willing to build for £1890

D. Burton's certificate of 2/3rds completion by the Cubitts February 2nd 1832, £1000 due to them.

D. Burton to Stephenson 6th February 1832

D. Burton's full "Specification for Erecting and finishing, building to contain Mr Babbage's Calculating Engine, Workshops &c. and of Alterations and repairs to the adjoining house in East Street Manchester Square": tender k document dated 12th November 1831.

PRO Chancery Lane Division

Chancery Lane, London WC1

Papers of the Crown Estate Commissioners (Formerly Commissioners of H.M. Woods, Forests and Land Revenues). The CONSTAT Papers or papers containing instructions from the Treasury to the Commissioners of Woods, Forests etc.. Papers relate to the construction of a building and workshops for Babbage's first Difference Engine next to his house in Dorset Street in 1831/32. :

CRES 6 152 volume H7 Pages 173-225

Office of Woods, etc to Treasury 30th April 1831

D. Burton to Office of Woods, etc 21st April 1831

Babbage to Decimus Burton 19th April 1831

Treasury to Office of Woods, etc 6th May 1831

Office of Woods, etc to Treasury 29th July 1831

D. Burton to Office of Woods, etc 1st July 1831

Babbage to Decimus Burton 19th April 1831

Babbage to Decimus Burton 1st July 1831

D. Burton to Office of Woods, etc 14th July 1831

Babbage to D. Burton 14th July 1831

Treasury to Office of Woods, etc 19th August 1831

Office of Woods, etc to Treasury 13th October 1831

D. Burton to Office of Woods, etc 24th Sept 1831

Babbage to D. Burton 16th September 1831

Babbage on making the workshops permanent 31st Aug 1831

Treasury to Office of Woods, etc. 31st Oct 1831

Office of Woods to Treasury 13th April 1832

Treasury to Office of Woods, etc 9th May 1832

CRES 6 174 volume F8 Pages 310-319

Office of Woods,etc to Treasury 22nd November 1842

Treasury to Office of Woods 7th November 1842

Extract of Lease of Babbage's land 1st Dec 1831

Treasury to Office of Woods, etc 21st December 1842

Royal Society of London,

6 Carlton House Terrace, London SW1Y 5AG

Babbage/Herschel Correspondence

Volume 2 of the Herschel Collection (HS.2): 418 letters with Sir John Herschel beginning 1812. Both sides of the correspondence is contained in the collection. Also included are letters from both Babbage's mother and wife to Herschel and his replies to them.

Volume 20: Herschel's replies to Babbage's letters

Box 27 Items 42 to 54 Herschel's 1827/28 correspondence relating to Babbage's Calculating Engine when Herschel was superintendent of the work during Babbage's year long continental tour:

42 Herschel's notes for Babbage 13th Feb and 17th Apr 1828

43 Clement to Herschel 5th Dec 1827

44 Clement to Herschel 1st Feb 1828

45 Clement to Herschel 27th Mar 1828

46 Clement to Herschel 10th Jun 1828

47 Clement to Herschel 21st Jul 1828

48 Herschel to Clement 24th Jul 1828

49 Herschel's Accounts 1828

50 H. Goulburn to Airy 15th Sept 1842

51 Herschel to Goulburn 1842 report on Babbage's Difference Engine

52 Herschel to Babbage n.d.

53 William Parsons to Herschel 6th Jul 1852

54 Herschel Notes and cuttings n.d. and 1828

Other Collections

Mss of 5 Scientific papers submitted by Babbage to the Royal Society 1815-26

25 Letters Babbage to Sir J.W. Lubbock 1829-60

Letters and papers of three committees set up by the Royal Society in 1823, 1829 and 1831 to consider Babbage's difference engine and the question of Government aid towards its construction. DM.4.129-50.

Museum of the History of Science,

Old Ashmolean Building,

Broad Street, Oxford OX1 3AZ.

Harry Wilmot Buxton Collection

Buxton Ms 3: Neat fair copies in a single volume of the following Babbage Mss: (a) The Science of Number reduced to Mechanism, dated part way through November 1822 otherwise undated; and (b) On the mathematical powers of the Calculating Engine, dated December 26 1837. The volume bears a watermark for 1832. 1 vol folio.

Buxton Ms 5: Statement of the circumstances ... by Sir Harry Nicolas, 1843 Printed.

Buxton Ms 7: Babbage Mss notes and some correspondence dated 1822-1858 and 1 undated mainly concerning his engines. Another copy of Ms 5 above and a printed copy of Babbage's letter to the Head of Government (Earl of Derby) dated June 8th 1852: the letter deals with the history of Babbage's relations with Government; it has manuscript annotations requesting its return to Babbage which seem to indicate that it was circulated by Babbage on loan to various persons.

Buxton Ms 8: Transcriptions of Babbage Mss dated 1824-1843 by Buxton on Babbage's engines, 1 file.

Buxton Ms 9: The science of number reduced to mechanism, notes and drawings on the engines, letter from Babbage to Buxton (1863).

Buxton Mss 16 and 17: Ms of the Memoir of the life and labours of the late Charles Babbage, ... by H.W. Buxton (1871). 2 volumes.

B. MINOR COLLECTIONS

Board of Longitude Papers

Royal Greenwich Observatory

[Now transferred to Cambridge University Library]:

J.F.W. Herschel was appointed a commissioner of the Board of Longitude on 7th June 1821: he attended a meeting of the Board that day and also on 1st November 1821. This latter date is significant as it was the day Babbage considerably revised the design of his first Difference Engine. Suprisingly Babbage's Difference Engine is not mentioned in any of the BoL's papers, but a note for November 1825 did say that Babbage was in possession of a set of logarithms more accurate than Taylor's.

Wanganui Regional Museum,

PO. Box 352, Wanganui, North Island, New Zealand.

Collection of Charles Babbage and Family Papers, Box 22:

Donated by Henry Herschel Babbage (1873-1946) and Mrs Jean Babbage.

Babbage's manuscript for his autobiography Passages from the Life of a Philosopher (1864), with many corrections, insertions etc., in envelopes bearing postmarks dated 1862- 1863. Published version in some instances considerably revised from original manuscript draft version(s) especially in the chapter on the 1862 Exhibition and Babbage's views on Disraeli: the published versions of the condemnations are quite mild in comparison with the original Ms versions. The Chapter on the Difference Engine is entitled Boy's Own View of Calculating Machines.

Babbage Ms copy of an advertisement from the Times March 3rd 1835: "Calculating Machines. The advertiser engages to furnish such machines, having three orders of differences of 5, 4, and 3 places respectively, and capable of calculating any table of six places of figures, with the third difference constant. The price of each machine will be £40 and the advertiser will demand no money until the machine is delivered perfect according to the above conditions. Apply post-paid, to Delta care of Mr. Robertson, Mechanics Magazine Office, Peterborough Court, Fleet Street." Apparently placed by Alfred Deacon, who constructed a fragment of a Difference Engine (non-printing) having read Lardner's article (1834) in the Edinburgh Review. Babbage later bought a copy of Deacon's machine and praised it very highly.

Alfred W. Van Sinderen,

310 Orange Street, New Haven,

Connecticut, USA

Private Collection

Mr A. Van Sinderen is an avid collector of Babbage memorabilia. He owns well over 120 letters written by Babbage and original copies of almost all his printed papers. Specific items in his collection include:

Babbage's Account Book whilst he was at Cambridge (1810- 1816), which also have a few pages towards the back dealing with his deposits and withdrawals from his bank account at Praeds covering the years from 1825 to 1827. A number of entries record payments made to Clement, the engineer who worked on the Difference Engine. Again this item was once in the possession of Richard H. Babbage (Babbage's great grandson), who has made a number of notes in pencil on several of its pages.

Babbage to Alexander Dallas Bache 8th Aug 1854. A 23 page letter in which Babbage turns down the offer of a job with the US Lighthouse Board to implement his scheme for occulting lighthouses. This is a significant letter: much of it gives details of Babbage's early life and work on the calculating engines.

North Carolina State Archives, USA

Francis Lister Hawks Papers

Private Collections 574: mentions an undated interview with Babbage in England about his mechanical calculator.

British Library Manuscripts Department,

British Museum, Great Russell Street, London WC1.

Reserved Photocopy 813:

Letters to and from Babbage 1829,1862, n.d..

i) Babbage to Harriet Isaac (née Whitmore: Babbage's sister- in-law) Dorset Street 22nd Dec 1829: re Babbage's children and mentioning that he was dealing with the government again re the engine: " ... I am in correspondence with the government still but in [a] much better position than before. I still think that the machine will end, but I ask nothing more for the protection of my character than that the House of Commons should print the whole correspondence. I do not think I should care to add a word. ..."

Reserved Photocopy 3625

re 1862 Exhibition 25th August 1862

Reserved Photocopy 2845 (Box 66)

Letter Babbage to John Timbs Esq. Dorset Street, Manchester Square 29th November 1859. Timbs was author of a work which described Babbage's Difference Engine. Babbage thanks him for a copy of his very interesting volume and, from the portion of it which he has read, for the publicity and justice given to Mr Gravatt's long continued and unostentatious labors in assisting the Scheutz's.

Scott Polar Research Institute,

Lensfield Road, Cambridge

Franklin Collection

MS 248/60 Jane Franklin's Journal (21/2/1835-21/6/1835) reference to Babbage's calculating machine.

MS 1488/1 Collection of letters from John Franklin to William Fitton in which the promotion of Babbage's machine is discussed.

Bristol University Library,

Tyndall Avenue, Bristol BS8 1TJ

Brunel Collection

Sir Marc Brunel's diary 1823, entry for 10th March:

Mr. Babbage's Calculating Machine

"Called on Mr C. Babbage who shewed me his machine for solving calculations to a very extensive reach - It is extremely ingenious and will most certainly answer; but the expence will be very great and the labour still greater."

Mrs A. German

Thurlby Hall,

Thurlby-by-Lincoln,

Lincolnshire

Bromhead Collection (Private)

January 2nd 1822, Slough, Babbage to Bromhead: Sorry that he has not written for a long time; "a kind of spell has interrupted my good intentions". Is staying with Herschel. Has been to Switzerland and North Italy with him. Returned in October [1821]. Since that time whole of his family has been very ill. Youngest son, Edward, has died. Essays [on Philosophy of Analysis] may be published in the Cambridge Transactions, but are a bit too long.

February 9th 1822, Devonshire Street, Portland Place, Babbage to Bromhead: Has delayed writing for several weeks hoping to communicate matter of extraordinary kind. Has been compelled to wait for the mechanical labors of workmen. His scheme has been perfected in theory for nearly two months. Babbage has contrived an engine which will by mere animal force calculate any tables however complicated provided their nth differences can be regarded as constant for certain periods and in some few cases even this condition was not necessary. Is constructing an engine for D²=Const. Not satisfied with just the calculation, when complete it will place type in its proper place from which tables may be printed. Engine might cause a revolution in mathematics.

27th May 1822 Devonshire Street, Portland Place, Babbage to Bromhead: Engine for calculating any tables requiring constant second differences has just been completed. Its principle is simple; could be extended to 50 figures and ten orders of differences. The engine on a large scale will solve equations.

28th May 1822, Dudmaston Shropshire c/o W.W. Whitmore, Babbage to Bromhead: Hopes that the calamities of his own family are over: has lost his youngest son just a few days after his last letter. Left London few days after his letter to Sir Humphry Davy had been published. Is concerned with the state of Sir William Herschel's health. Is not intending to do any more to the Engine till he returns in October. Hopes government will take up his Engine: 'It would be disgraceful to the country that I should be compelled to repay myself by printing tables and consequently keep secret the machinery which is capable of producing so much'. Fears he may have to visit Slough shortly.

14th September 1822 Dudmaston, Babbage to Bromhead: Hopes to return to London end of October. Hopes to find sufficient reasons to induce him to continue with the Engine. Has been examining some new views on the method of finite differences which have arisen from contemplating a certain engine which he had contrived on paper. How curious it was that the contrivance of a mechanical engine could guide the mathematical analyst in his studies into new properties and combinations.

17th December 1822, Devonshire Street, Babbage to Bromhead: Has found out some curious analytical difficulties by means of his Engine. Has not done much to the thing itself.

23rd March 1823, Devonshire Street, Babbage to Bromhead: Dugald Bromhead Babbage has just been born. His Engine has made a vast sensation in London: many have wanted to see it. Davies Gilbert has had many interviews on it with Sir Robert Peel and also with the Chancellor of the Exchequer. The Royal Society will be asked to report on it to the Government. A Committee of the House of Commons might be assembled to approve its merit and value. It has already cost Babbage much money and will cost a lot more. Is constructing a larger machine with five orders of differences. Is dissatisfied with his badly-made model. An infinite variety of equations of finite differences are within its reach; as well as all astronomical tables. Many engineers believe the construction can be carried to an unlimited extent. If Bromhead was to visit London he could read the latest work Babbage had done on his Essays on the Philosophy of Analysis. With respect to the Engine the French say, first it is not new (not Babbage's but Pascal's) and secondly it is not true, but impossible.

12th June 1823, Devonshire Street, Babbage to Bromhead: Babbage had hoped to see Bromhead at the Greenwich Visitation. On Davies Gilbert's interview with the Chancellor who had refused to sponsor the invention. How Brougham was consulted, and also Ricardo and W. Smith. How Babbage had consulted R. Smith and Scarlett, and several other MPs all of whom promised to speak favourably on it in the House of Commons. Chancellor now willing to advance the money. Has increased the number of workmen on the project as well as the expenditure. The Royal Society had reported favourably on his Engine.

10th August 1822 Devonshire Street, Babbage to Bromhead: how he was just off on a tour of the country to see everything he could get access to relating to machinery. How he had just received £1500 from the Treasury for the Engine with the prospect of more should he require it. How the engine was progressing satifactorily and will continue in his absence.

Buckinghamshire Record Office,

County Hall, Aylesbury:

Bulstrode Collection

Correspondence of the Edward Aldophus Seymour (St. Mawr), 11th Duke of Somerset: 13 letters (1830-1849) from Babbage to the Duke.

5.Nov.1830: On the hiring of a new and competent draughtsman [C.G. Jarvis?] to work on the Calculating Engine.

25.Feb.1834: On Babbage's troubles with the Government and Clement over the Difference Engine; how he had on a previous occasion almost given up the project.

12.Aug.1839: About arranging a visit for the Duke and his friends to see the Difference Engine.

Biblioteca Dell'Accademia Delle Scienze di Torino.

Turin, Italy.

Plana Collection

Elevation of a position of Mr. Babbage's engine for calculating tables by the method of Differences as arranged in 1834 (2 copies). [the fragment of DE No. 1]

Cart 22338-346 4 letters Babbage to Angelo Sismonda: 3rd Sept 1840, 1st Dec 1840, 24th March 1841, 24th March 1842 together with translations.

See also La Macchina Analitica. Un Secolo di Calcolo Automatico by Mario G. Losano (Etas Kompas Libri, Milano 1973)

Centre national d'histoire des sciences,

Bibliothèque Royale de Belgique, 4 boulevard de l'Empereur

Bruxelles 1, Belgium.

Quetelet Collection académie royale de Belgique correspondance d'A. Quetelet No. 267:

Letters from Babbage to Quetelet.

Babbage to Quetelet 13 Nov 1826: On the then just recently published half volume of memoirs of the Astronomical Society containing data on 2800 stars.

Babbage to Quetelet 2 Dec 1829: How a committee of practical engineers had just finished examining Babbage's engine concluding it to be the most perfect piece of workmanship they had ever seen. Babbage remarks that he had just increased its mathematical power. How time and money were required to complete it.

Babbage to Quetelet 24th Dec 1831: On how he was very occupied with the calculating engine. That he had laid the first stone that day of the building intended to house it. About a year and a half more would be required to complete the engine.

Babbage to Quetelet 27th April 1835: On Babbage's researches into Calculating Machinery, on his frustrations with the British Government, give some details on his new machine.

Earl of Rosse,

Birr Scientific Heritage Foundation,

Birr Castle, Birra, Eire

Rosse Papers (Private Collection)

Letters and papers 1829, 1852 and 1862 letters from Babbage to William Parsons (1800-1867), 3rd Earl of Rosse, President of the Royal Society and Lady Rosse, about government support for his scientific work and inventions.

J/1 Copy of the Printed Minutes of the Council of the Royal Society 12th February 1829 and the Report of the Committee of the Royal Society convened to examine Babbage's Calculating Engine February 1829.

J/1/2 Letter Babbage to Lord Rosse 30 May 1852: enclosing copies of his woodcuts and the 1840 lithograph of the Analytical Engine. Babbage remarked that the Penny Magazine had made a woodcut of his Difference Engine (No.1) but that it was never used and had gone missing. Claudet was to make a photograph of the fragment in King's College.

Waseda Daigaku, Toshokan

(Waseda University Library),

6-1 Nishiwaseda 1-chome, Shinjuku-ku,

Tokyo, Japan

Babbage Collection

A. Manuscript Materials

Babbage, Charles. Manuscript Journal. 1820-1825

68 pages (incl. 13 blank) plus 5 leaves of additional notes by Babbage loosely inserted; vellum lower cover damaged.

On the appointment by the Duke of Wellington, upon the recommendation of the Royal Society, of Thomas Colby to carry out the trigonometrical survey of Ireland. On the Government's rewarding of Marc Brunel for his invention and development of the Block Making Machinery at Portsmouth, and the difficulties he experienced in obtaining this reward. Dinner at the Observatory in Paris in July 1821. Baily's observations on the errors in the Nautical Almanac. "May 10 [1822] Calculating Machine nearly finished". South and Baily's notes on the Nautical Almanac. On meeting the Prince of Denmark. Visitation of Greenwich 1822. March 1st [1823] meeting with Davies Gilbert to discuss calculating engine. 20 March 1823 Meeting with Davies Gilbert on calculating engine. On the calculating engine and the opinion of the Board of Longitude. On a letter from Sir R. Peel to Sir H. Davy and the Royal Society, re calculating engine. Meeting with Lord Stanhope, learns about Lord S.'s father's machine. Meeting of the Royal Society to discuss calculating engine.

Babbage, Charles. Manuscript Account Book with Praeds, Mackworth and Newcombe. Inscribed 'Cha. Babbage, 1816 to 1819'. pp. 38, a few pages missing [1817-1819]. Vellum.

Babbage's income derives principally from ground rents and subs from his father, £300 a year before his marriage, £450 afterwards. Balance grows from £126 in Oct 1814 to £2355 in Dec 1822.

B. Printed Materials

Impression from a woodcut of a small portion of Mr. Babbage's Difference Engine, No. 1 ... Plate printed June 1853. Used a frontispiece to Passages etc., 1864.

"Impression from a Copper Plate punched with figures. 1822". pp. [2]; two copper plate impressions of a page full of the digit 5, one done in black on white and the other reversed.

Anastatic Plate of a small portion of Mr. Babbage's Difference Engine, No. 1, the property of the Government at present deposited in the Museum of King's College, Somerset House. pp [1], printed March 1853.

Impression from a Woodcut of a Small Portion of Mr. Babbage's Difference Engine, No.1 ... pp.[1], printed June 1853. Ms. note on verso on question of money spent on engine.

History of Mr. Babbage's Calculating Engines. pp.50 and double page table. A reprint of two articles specially prepared by Babbage for inclusion in his intended History of the Analytical Engines. The two articles were "Statement of the circumstances attending the Invention and Construction of Mr. Babbage's Calculating Engines" from the Philosophical Magazine, Sept 1843. p.235 and the Menabrea/Lovelace article published in Scientific Memoirs, vol. iii, p.666 (item 8-9). Pages 1-50 + plate in Babbage's Calculating Engines by H.P. Babbage (London: 1889) is reproduction of this item.

A Catalogue of a Collection of Engineers' Tools & Plant, Used by the Late Mr. Babbage, including ... which will be Sold by Auction by ... Dorset Street ... Friday, the 1st of March, 1872. Title and pp. 2-15. "I sold the contents of the workshop on 1st March and two following days. I reserved a lathe or two, a small planing machine, and some smaller tools." H.P. Babbage.

Royal Astronomical Society,

Burlington House, Piccadilly, London.

RAS Letters

Letters from Babbage to the Society:

1820 - 1, 1822 - 1, 1823 - 4, 1844 - 1, 1847 - 1, 1852 - 1, 1870 - 1.

RAS Manuscripts

Baily Collection folder 35 RAS Baily 1

Babbage to Francis Baily letter dated 15th January 1823: on a possible appointment for Babbage with the Equitable Life Assurance Association, and on how his Difference Engine might be applied to the tables and balances of a life assurance company.

Official Publications Library,

Division of the British Library,

British Museum, Great Russell Street,

London WC1.

Parliamentary Debates (Hansard)

May 15th 1835 Vol XXVII(3rd Series) pp. 1154-1155

Cobbett's comment that £1,500 to be voted from Civil Contingencies for Babbage's machine was an unprincipled waste and squandering of public money. Chancellor's (Spring-Rice) reply that none of the money spent so far had gone into Babbage's pocket. Warburton's comment that the Treasury should prepare a report on the Engine and the possibility of its completion.

March 27th 1843 No statement recorded but see Times of 28th March 1843 page 4 column 6 re Miscellaneous Estimates

Hawes suggested that the government should purchase the drawings of Babbage's engine. Sir Robert Peel replied that it would be a waste of money to spend £50,000 on the development of an calculating engine that might not work despite Babbage's ingenuity.

Journal of the House of Commons

Volume for 1823 p. 330 22nd May 1823 Papers and correspondence between Royal Society and the Treasury, and Babbage's letter to Sir Humphry Davy ordered printed.

Records of sums expended out Civil Contingencies category 5 Various Public Services on the construction of Babbage's Difference Engine reported to Parliament in Appendix B of the Journal. NB excludes costs of building works

Volume for 1824 p.658 re spending in 1823 £1,547

Volume for 1830 p.786 re spending in 1829 £1,500

Volume for 1831 p.1063 re spending in 1830 £3,600

Volume for 1832 p.845 re spending in 1831 £2,000

Volume for 1833 p.919 re spending in 1832 £3,657-16-6

Volume for 1834 p.768 re spending in 1833 £1,782-11-4

Volume for 1835 p.561 re spending in 1834 £1,200-13-6

Total £15,288- 1-4

1823 Accounts and Papers(2) Vol XV p.9

Paper no. 370 23rd May 1823: Babbage's Letter to Sir Humphry Davy and the Correspondence between the Treasury and the Royal Society.

Bodleian Library, Oxford

Somerville Collection 19 (Folder MSB-1)

Papers of Mary Fairfax Greig Somerville and William Somerville

A number of letters mention the difference engine. Including:-

Letter Babbage to MS 14-June-1828 on the Difference Engine

Letter Babbage to MS 14-Dec-1833 "When will you come and give another day to the Engine?"

St Andrews University Library,

St Andrews, Scotland

J.D. Forbes (1809-1868) Collection,

21.9.1831 Babbage to Forbes: Refers to an "infernal machine" and the Calculating Engine and general scientific matters. (n.p.,n.d.)

13.10.1831 Forbes to Babbage: "I wrote to Mr Babbage from York in answer to his letter received there in the end of September" [Not Extant]. "In answer to his of Oct 7th" [Not Extant]. Refers to "Your Machine". (Posted Edinburgh).

25.1.1832 Babbage to Forbes: Brewster's analysis of the solar spectrum; "my buildings for the engine are far advanced". Mentions that base plate for the calculating engine has had to be recast.(Posted Cambridge)

10.2.1832 Forbes to Babbage: Seeking advice on instrument makers (Posted Edinburgh).

18.4.1832 Forbes to Babbage: About getting sparks from a natural magnet; scientific news; "I hope the machine thrives". (Posted Edinburgh).

See also Life and Letters of James David Forbes pp. 69 and 70: These entries refer to taking breakfast with Mr Lyell. Met Mr Babbage. Spoke of his machine as a work of great anxiety, May 1831.

Edinburgh University Library,

George Square, Edinburgh EH8 9LJ,

Scotland

Special Collections

Letter from Babbage to Mr. Booth of Duke Street, Portland Place dated 28-Aug-1822 requesting that he grant copies of his letter to Sir Humphry Davy to any who applies in his name. In La.III.366

Babbage is mentioned in a letter of Sir R. Christison to P.G. Tait dated Tuesday morning, 21 November [1871]. On an obituary on Babbage and the obituary itself as published in the Royal Society of Edinburgh's journal. Christison said he saw Babbage's wonderful machine in 1838, and describes how Babbage yawned all the time during his explanation of it. Gen.2169/42 E83/82

Crawford Library

Royal Observatory for Scotland,

Edinburgh

Babbage's Personal Mathematical and Scientific Library

(See The Scientific Library of Charles Babbage by M.R. Williams Annals of the History of Computing 3 no. 2, July 1981 and Tucker R. Mathematical and Scientific Library of the Late Charles Babbage, C.F. Hodgson and Son, London 1872)

Sotheby's Sales

The following items of Babbage Mss were recorded in the catalogues (1966-1988) as sold by the Department of Printed Books, Autograph Letter and Manuscripts, Sotheby's, the auctioneers, 34-35 New Bond Street, London W1A 2AA.

Lot 482 18.7.67

Babbage (Charles), A.L.s. 1 page, 4to, 1 Dorset St., 9 July 1838, to Sir Benjamin Hawes, M.P. for Lambeth, making an appointment to see him in view of the writer's hope of "getting a question put in the H. of C. relative to the Engine" (viz. the calculating machine, which Babbage had been constructing for 16 years, a cause to which his correspondent was sympathetic.

Lot 483 18.7.67

Babbage (Charles) "Report to the R^t Hon^ble the Chancellor of the Exchequer relative to the Calculating Engine by Charles Babbage", Autograph Manuscript, signed, 2 pages, folio, 1, Dorset St., 2 February 1836, with integral blank leaf

In this interesting memorandum Babbage refers to his "new" calculating machine, whose principles he first worked out in 1834. Then he thought that it complemented his original model (under construction since 1823), now (he says) he has so perfected it that "it will also perform all those calculations which were peculiar to the old engine ... that in fact it completely supersedes the old engne". In the light of this, he recommends that the old machine be scrapped.

Lot 285 28.11.72

Babbage (Charles 1791-1871 scientist) Two A.Ls.s.:

a) 2 pages, 4to Dorset Street, 22 December 1829 to Harriet Isaac, referring to his "machine" ("I am in correspondence with government still but in a much better position than before ... I ask nothing more for the protection of my character than that the House of Commons should print the whole correspondence...")

b) 2½ pages, 8vo, Dorset Street, 26 November 1862, To his niece, Sophy, returning a letter written by Herschel and giving news of himself ("Besides my constant work at the machine I am now making a book ... You will I have no doubt be amused at some portions of it for there is more of worldly affairs than of science in it ... ") the first with integral address leaf, postmark and seal.

Lot 260 25.6.75

Babbage (Charles 1791-1871, inventor of the calculating machine) Remarkable and important A.L.s. about his recently constructed calculating machine, 3 full pages, 4to, 19 June 1824, almost certainly to Henry Thomas Colebrooke, President of the Astronomical Society, to which Society had made the first announcement of his machine and whose first gold medal was bestowed on him on 13 June 1823 (a fact adverted to in this letter), he points to what strikes him as the novelty and importance of his machine in relation to those of earlier and inferior design (Pascal's Leibniz's etc.):

... The great principle which distinguishes mine from all these is that it proposes to calculate a series of numbers following any laws by the aid of differences and that by placing in it a few figures at the outset a long series of numbers are produced -The method of differences in a very wide sense is the mathematical principle. A machine to add a number of arbitrary figures together cannot possibly save much time or trouble because each individual figure must be placed in the machine but the case is altered when those figures follow some law the insertion of a few at first determine the magnitude of the next and these the succeeding -It is this constant repetition of similar operations which renders the calculation of tables a fit subject for the application of machinery -Another point in the present machine is the simplicity of its essential parts ...

He then outlines five experiments he is conducting for the perfecting of the print-out mechanism, mentions the government grant he has received (from the Civil Contingencies fund) and says he has sent two specimens of the copper plate and a copy of his Letter to Sir Humphry Davy, contemporary endorsement on verso of second leaf.

conclusion of letter is as follows:-

... I understand the medal was for a Calculating machine which was finished when it was awarded and not for the Prtn^g part which is not yet made.

Might it not be desireable to notice the very liberal manner in which Government have behaved and at the same time to restate the principle on which the Chancellor of the Exchequer acted -That it, the engine, was of importance to the country and could not possibly repay the contriver by the [del:small] sum [del: it would] which its products would sell for. I have sent two specimens of the copper plate and a copy of my letter to Sir H. Davy. If there is any other information relative to this that I can furnish you with I shall be most happy to do so or if you would like to see the progress I have made in the new machine it shall be visible at any time.

I remain my dear Sir

Yours faithfully

C. Babbage

19 June 1824

Resold as Lot 156, 27th September 1988

[illustration in catalogue]

Lot 205 24.7.78

Babbage (Charles) A.L.s. 1 page, 4to, Dorset Street, 4 May, no year (watermark dated 1829), evidently to a printer, discussing matters relating to proofs and the cost of corrections and requesting that a copy of the proofs be sent to the Lord Chancellor, unobtrusively repaired on verso.

Lot 1132 2.5.79

Babbage (Charles) Autograph account book kept by him while at Cambridge between 2 October 1810 and 1 June 1816 and while residing in London between 10 January 1825 and 31 December 1827, recording payments of tutors' booksellers' and tailors' bills, and payments to the Royal Society (of which he elected a member in 1816), Clement (the engineer employed in constructing the calculating machine), and to many other individuals, c. 40 pages, excluding blanks, pencilled annotations by R. Babbage, a descendant of Charles Babbage, boards, worn, quarto.

SURVIVING MACHINERY, PARTS AND MODELS

OF BABBAGE'S DIFFERENCE ENGINE No.1

Science Museum,

Exhibition Road, South Kensington, London SW7

Portion or Fragment of the Difference Engine put together in 1832. It is the most important of the fragments to have survived. It was assembled by Clement for Babbage as a test piece to illustrate the actions of the calculating part of DE1. It comprises of 18 figure wheels arranged in three columns; a special driving mechanism was developed for it. It contains just under 2000 components.

Following cancellation of the DE1 project it was transferred by the Government to the King's College Museum, London in 1843, where it remained for 29 years. In 1862 it was placed on show at International Exhibition held that year. Subsequent to that it was lent to the Science Museum by the Board of Trade. INV-1862-89.

There is a replica of this model in the Smithsonian Institution, Washington made in 1957 by Munro Ltd for IBM.

Trial Model for part of Babbage's Difference Engine No. 1. Presented by University College London. One of the five or six made by H.P. Babbage from the surviving parts of Difference Engine No. 1 in 1888. INV 1967-70. This fragment has one figure wheel adding to two.

Spare parts and trial pieces (brass/gun metal) from Babbage's Difference Engine No. 1. Presented by King's College, London. INV 1971-267. Included in the collection are 2 Framing Plates, a Bolting Lever, a Carry Warning Lever, some Roller Levers, a Lower Calculating Wheel, several Number Rings, an uninscribed Figure Wheel Drum, a Snail Wheel, some Plate Spacers or Columns Sockets and a set of 4 gear wheels (of unidentified purpose) with triangular cog teeth similar to those found in the Oxford Museum of the History of Science.

Whipple Museum of the History of Science

Free School Lane, Cambridge

The museum is the depository for one of the five fragments of the calculating part of Difference Engine No. 1, as assembled by H.P. Babbage from the surviving pieces in 1888. The Whipple Museum's model was originally kept at the Cavendish Laboratory at Cambridge, but was transferred to the museum in recent times for safe keeping. This particular model has two figure wheels adding to three.

Royal Albert Memorial Museum

Queen Street, Exeter, EX4 3RX, Devonshire.

Parts of the Difference Engine, Inventory Item 440/1974

(Stored in a cardboard box in the museum's attic)

In August 1869 Babbage attended the meeting of the British Association for the Advancement of Science held in Exeter that year. During the meeting he presented a number of the parts of made for Difference Engine No. 1 to the newly opened museum. Babbage's original note written in pencil, which accompanied the parts (written on the back of a British Association field excursion ticket dated 21st August 1869) reads as follows.

"Mr Babbage has brought for the Exeter Museum portions of the Difference Engine. Work executed about 50 years ago."

Parts in the collection of which there are 9 include:

A double-ended Roller Lever for locking a Lower Calculating Wheel, an Index Pointer for indicating the figure on a Figure Wheel (mark not inscribed), an unfinished single-ended Roller Lever, part of a Bolting Mechanism, part of a Carrying Lever, a Carry Warning Lever (double-ended), Brass cut-out for 4 cog wheels (not DE1 material), Small toothed Rack (ca 2" long) (not DE1 material), Small boxed (open-ended) assembly of three interconnecting cogs whose purpose is unknown.

Museum of the History of Science,

Old Ashmolean Building, Broad Street, Oxford OX1 3AZ.

Harry Wilmot Buxton Collection

The museum has a fragment of the Difference Engine presumably that one given to Buxton by Babbage, made from the leftover parts of the Difference Engine which he purchased from the Government in 1843. This fragment is on display on the 1st floor. It has been incorrectly assembled.

Identifiable Parts included in assembly:-

2 Framing Plates, Carrying Lever, Framing Plate Spacers or Column Sockets, 4 x Upper Calculating Wheels, 3 x Lower Calculating Wheels, 1 x Figure Wheel, 3 x Carrying Detent Levers, 2 x Bolting Prevention Levers, 1 x Carrying Detent, 2 x Bolting Arms, 2 x Bolts (assembled), parts for a Bolt (disassembled) and 3 springs for same, 1 x Snail Wheel attached to a Lower Calculating Wheel, 4 x Roller Levers (3 of which double ended), 2 x Figure Wheel Indicator Arms, 2 x Outer Inclined Planes, Wheel with triangular teeth and crown pin teeth, Some drum-like pieces approx 2½ inches diam.

Howard Aiken Computation Laboratory,

Harvard University, Cambridge, Mass. USA

During the 1930s it was reported by Howard Aiken that Havard possessed one of the fragment's of Babbage's Difference Engine made by H.P. Babbage. This is still to be found in the lobby of the laboratory. See "Babbage and Aiken with notes on Henry Babbage's gift to Harvard of a portion of his father's Difference Engine" by I. Bernard Cohen in Annals of the History of Computing December 1988. This model has one figure wheel adding to two.

Havard University Library:

University Archives I.5.150; Eliot C.W., Box 75,1886: Letter H.P.Babbage to the Principal of the University 25th Nov 1886 offering the model as a gift to the university.

University Archives V 298.2005. File: Babbage R.H. Instructions how to operate fragment by H.P. Babbage and History of Fragment.

Jean Babbage's Collection,

Auckland, New Zealand:

H.P. Babbage's instructions how to operate the fragment of the adding mechanism of the Difference Engine no. 1, and the fragment itself, one of five or six assembled by him in 1879.

[Note: Some of her collection has been donated to the Wanganui Regional Museum. The fragment itself is on show in the lobby of the engineering consultancy, Babbage and Partners, in Auckland.]

Macleay Museum,

University of Sydney, Australia

10 cog wheels, rods and other components from the Difference Engine and the Analytical Engine. Donated by Dr N.F. Babbage.

NOTES BY H.P. BABBAGE

a) Extract from page 224 of

Memoirs and Correspondence of Major-General H.P. Babbage

by Henry Prévost Babbage

London: William Clowes & Sons, n.d.. (ca 1910))

Difference Engine

Some unfinished parts of the Difference Engine came to me as waste metal, and not long after I returned from India I found that with the part put together, which was then in the Museum of King's College, Somerset House, Strand, London there was nearly if not all of the Difference Engine, together with a lot of more or less finished pieces, enough to put together the calculating part of the machine. Very few of the frame plates were there; they had mostly been cut up by my father for other work.

I conceived the idea of making fresh frame plates and putting the pieces in the positions they would occupy in the completed machine, and I spent a good deal of money and much time towards this object, but I soon found that with my means it was entirely impossible to do anything useful, and after consulting some friends I decided to abandon the project.

About that time I learnt that the workshop of Clement, where the work was done, had been broken up and unfinished material had been melted, so I decided to dismantle the work which I had put together, and sent the whole to the melting pot. So nothing remained of the Difference Engine beyond the small pieces put together in 1833, now in the Science Museum at South Kensington, and five small separate pieces of it which I put together and distributed as follows: two of five cages each, to show two figures added to three, one for myself and one I sent to Havard University, USA, and three pieces of three cages each to show one figure added to two.

b) Extract from Babbage's Calculating Engine's (1889)

Conclusion by Henry Prévost Babbage p. 341 (October 1888)

... The rest of the machinery was disposed of at something like the price of old metal. My father bought some which he cut up and used as he found occasion during his lifetime. What was left came to me after his death in 1871, and from a few sample pieces were put together. One of these I sent to Cambridge University, one to University College, London, and another to Owens College, Manchester. One I sent to America, and two more I have myself. All the rest was melted up some years ago and about the same time some of the work which remained in Clement's workshop was, I heard, melted up on the works being closed by his nephew and successor. ...

PUBLISHED WORKS AND OTHER SOURCES

19th Century References and Original Sources

Babbage, C. (1822) A note respecting the Application of Machinery to the Calculation of Astronomical Tables, Memoirs of the Astronomical Society 1 p. 309. Written 2nd June and read before the society June 14th 1822. A short paper in which Babbage announces publicly his invention of an automatic machine using the method of differences as its principle for manufacturing mathematical tables (both calculating and automatically printing the results).

Babbage, C. (1822) A Letter to Sir Humphry Davy, Bart. President of the Royal Society, on the Application of Machinery to the Purpose of Calculating and Printing Mathematical Tables J. Booth, Printer to Royal Society, London, 1822. An open letter dated 3rd July 1822 to all members of the Royal Society in which Babbage elaborated in more detail on his Difference Engine and its advantages, and mentions several other calculating machines he had been working on. "Whether I shall construct a larger engine of this kind, and bring to perfection the others I have described, will in a great measure depend on the nature of the encouragement I may receive". Letter reached the ears of the British Government, who after a long while decided to sponsor the construction of such a machine.

[probably E. Smedley] (1822) The British Critic October 1822, Vol. XVIII pages 362-369 ART. III Letter to Sir Humphry Davy, Bart, President of the Royal Society, &c.&c. On the Application of Machinery to the Purpose of Calculating and Printing Mathematical Tables, from Charles Babbage, Esq. M.A. F.R.S. Lond. and Edin., Member of the Cambridge Philosophical Society, Secretary of the Astronomical Society of London, and Correspondent of the Philomathic Society of Paris. 4to 12pp Baldwin & Co. 1822.

[ ] (1823) Article on Babbage's Letter to Sir Humphry Davy on page 691 in Annual Register for 1822 Published London 1823 (Preface dated July 7th 1823).

Babbage, C. (1823) On the Theoretical Principles of the Machinery for Calculating Tables [Brewster's] Journal of Science 8 pp. 122-8. Letter to Dr. Brewster dated 6th November 1822. Another paper elaborating on the theory of the Difference Engine. More peculiar infinite series using a variation on the standard method of differences.

Baily, Francis. (1824) On Mr. Babbage's New Machine for Calculating and Printing Mathematical and Astronomical Tables Philosophical Magazine 63, May 1824, pp. 355-67.

Babbage, C. (1824) On the Determination of the General Term of a New Class of Infinite Series, Transactions of the Cambridge Philosophical Society 2 pp.325-77. Cambridge, printed by J. Smith. Title and pp.9. A paper written on 29th March and read before the Society on 3rd May 1824.

Brewster, David (1824) History of Mechanical Inventions and Processes in the Useful Arts Edinburgh Journal of Science 1 (1) pp. 141-51.

Colebrooke, Henry Thomas. (1825) Address of Henry Thomas Colebrooke, Esq., F.R.S., President of the Astronomical Society of London, On presenting the Honorary Medals of the Society to the Several Persons to Whom They had Been Awarded Memoirs of the Astronomical Society of London 1(2) pp. 509-12.

Babbage, C. (1825) Observations on the Application of Machinery to the Computation of Mathematical Tables

Memoirs of the Astronomical Society 1 pp. 311-14. Read December 13th 1822. Further elaboration on the theoretical possibilities using a Difference Engine. Several new infinite series listed. On the possibility of using a difference engine for calculating Sine tables by simple modification of the principles of the Difference Engine.

Babbage, C. (1826) On a Method of Expressing by Signs the Action of Machinery Phil Trans 116(3) pp. 250-65, Royal Society, London. Title pp. 16 and 4 plates (1 folding). Communicated 17th January and read before the Society 16th March 1826. One of the more important of Babbage's earlier papers. He wrote it hoping to win one of the Royal Society's first gold medals which were to be awarded that year. Much to his chagrin he did not win one. The paper itself was on a notation to describe the motions of machinery. He had noticed how difficult it was during the development of his Difference Engine by the mere inspection of mechanical drawings to know which parts were in motion at any particular moment in time and which were not. He therefore devised ca 1824 this notation to solve this problem. The notation itself consists of several parts: an indicating line for each piece in the machine drawn on a chart; a method of lettering each piece; the number of teeth etc on each part; the ratio of velocity between connecting pieces; lines to trace the course and type of motion from the prime mover to each moving piece; adjustments which can be made by the machine's operator; and a vertical series of symbols and lines called 'the Cycles' to chart out the action of the machine during one complete cycle of its operation.

Babbage, C. (1826) On the Determination of the General Term of a New Class of Infinite Series Transactions of the Cambridge Philosophical Society 2 pp. 325-77. A paper written on 29th March and read before the Society on 3rd May 1824. An interesting paper and important in the history of computing in which Babbage described how he arrived at a whole new class of infinite series by making his experimental first difference engine (1821) "eat its own tail" (term not used in this particular paper), ie. feedback the results from the output or table column into the first or second difference column of such a machine. The series developed in the paper, however, have abstract value only. Babbage shows how to obtain the solution for such series algebraically.

[ ] (1826) The Quarterly Review June 1826 p. 163, John Murray, London contains a note on Babbage's Engine.

Babbage, C. (1827) Notice respecting some Errors Common to many Tables of Logarithms Memoirs of Astronomical Society 3 Art. iv pp. 65-7. Paper written 5th March and read before the Society March 9th 1827. Babbage had noticed that several previous compilers of logarithmic tables had simply copied their predecessors' efforts including all their mistakes which were thus being perpetuated. Babbage traces these errors to two common sources.

Babbage, C. (1827) Table of Logarithms of the Natural Numbers from 1 to 108,000 Stereotyped J. Mawman, London Preface dated January 20th 1827. Dedicated to his friend Colby, principal surveyor of the Ordnance Survey of Ireland for whom the tables had been originally prepared. These tables were perhaps the most accurate hand-produced log tables ever produced and were standard issue in schools well into this century. Only nine minor errors were discovered in the first edition which were subsequently corrected. His figures were thoroughly checked against all previous editions of logarithmic tables: Callet, Hutton, Vega, Briggs, Gardiner, and Taylor; editions dated 1633 - 1804. Babbage paid particular attention to the actual format and layout of the printed page for the accurate use of such tables for which he conducted several 'psychological' experiments. Many different editions and reprintings both at home and abroad were made. A particularly interesting reprint was the edition dated 1834 produced for the Hungarian Academy of Sciences printed in black ink on green paper. Various editions and reprints are dated 1829, 1831, 1834, 1841, 1844, 1872, 1889, 1912 and 1915.

[ ] (1828) Mr Babbage's Calculating Machine Mechanics Magazine 10 (263) p. 64 (23 Aug 1828).

[ ] (1829) Minutes of the Council of the Royal Society relating to the Report of the Committee on Mr Babbage's Calculating Machine. February 12 1829. pp. [1] Privately Printed.

[Herschel, J.F.W.] (1829) Report of the Committee, appointed by the Council of the Royal Society, to consider the subject referred to in Mr. Stewart's Letter, relative to Mr. Babbage's Calculating Engine, and to report thereupon. (private). London: Clowes, n.d..

Babbage, C. (1829) On the General Principles which Regulate the Application of Machinery to Manufacture and the Mechanical Arts Article in Encyclopaedia Metropolitana Vol 8 1-84. A long article based on a series of lectures on Political Economy which Babbage had intended to give as Lucasian Professor but never actually presented. The work eventually became part of his book On the Economy of Machinery and Manufactures published in 1832.

Babbage, C. (1831) Specimen of Logarithmic Tables (21 Vols) B. Fellowes, London. An enormous psychological experiment carried out by Babbage to determine which tints of paper and colours of ink were least fatiguing to the eye when using logarithmic tables, for use on the output of his Difference Engine. The exercise consisted of reprints from two pages of the second edition of his Logarithmic Tables (nos beginning with 99,700). One hundred and fifty one tints of paper were tried out using ten different colour inks: light blue, dark blue, light green, dark green, olive, yellow, light red, dark red, purple and black. In the 21st volume metallic inks including gold, silver and copper on vellum and other coloured papers were tried out.

The main points which Babbage tried to find out were: 1) whether white paper was as good as light tinted paper, 2) whether black ink was preferable, 3) whether strong or weak light made a difference to the colour of the ink used, 4) whether daylight or artificial light made a difference, 5) whether peculiarity in the vision of individuals or their state of health made a difference, 6) which colour inks or paper were the most agreeable to the majority of users.

The following conclusions were made: 1) black ink on white provided the greatest contrast and was thus best, but black ink on light tinted paper was best in strong sunlight, 2) dark coloured papers were always more fatiguing, but if used should have matched or blended coloured inks for best results, 3) the best coloured ink for individuals with poor vision varied between the individuals, 4) whilst white paper was always preferable, the best coloured paper was bluish green with a modest hue.

Possibly only one copy of the work was ever produced; this is now in the Crawford Library of Royal Observatory, Edinburgh.

Details of the experiment can be found in the Edinburgh Journal of Science New Series 6 (1832) pages 144-150.

Babbage, C. (1831) Table of Logarithms of the Natural Numbers from 1-108,000 on Different Coloured Papers B. Fellowes, London. Another experiment using different coloured papers, but with black ink only. Again only one copy is in existence (in the Crawford Library). There are 28 volumes, each of which is a copy of the whole edition of the book of log tables. The first four volumes are printed on pink paper, the next four on green, three on blue, four on salmon, three on brown, three on purple, and four on yellow. In each of these starting with a dark shade and gradually getting lighter through the book until by the end of the volume the paper was almost white. Three further volumes were added having all pages with identical colour: fawn, yellow and white, bringing the total to 28 volumes.

Babbage, C. (1832) On the Economy of Machinery and Manufactures Charles Knight, London. Perhaps Babbage's most important work in addition to that done on the Calculating Engines and for which he was to receive much acclaim during his own lifetime. It was to run into many editions and be translated into several different languages. It is largely a work on Political Economy, perhaps the first real attempt at a scientific approach to the question of an industrial economy. It is based to a large extent on his own personal research that he conducted in connexion with the Difference Engine, to ascertain what various mechanical processes and techniques were being used in order to improve that machine's design. Visits were made to hundreds of different firms all over Britain and the Continent. In his preface dated 8th June 1832 he says that the research was undertaken "for the purpose of endeavouring to make myself acquainted with the various resources of mechanical art, I was insensibly led to apply to them those principle of generalization to which my other pursuits had naturally give rise." The book is thus a summary of those economic laws and principles which apply to an industrial nation and its manufacturing concerns, amply illustrated with hundreds of contemporary and historical examples. It was written with the interests of both sides of industry in mind, both masters and workmen. It is regarded as a pioneering work on 'operations research' covering among many other things: regulation of power, control of the use of raw materials, division of labour, work and time studies, location and size of firm, stock control and depreciation of machinery and its replacement. It can still be read today with profit.

The second edition (1832) contained three new chapters. In the third edition (1833) six chapters were extended considerably and the new chapters included in the second edition were put in their proper sequence. Several other minor additions were also made. The fourth edition (1835) added only an index. Reprints were made in 1841 and 1846.

Publicola (1832) Mr Babbage's Calculating Machine Mechanics Magazine 17 (466) p. 256 (14 July 1832).

[ ] (1832) Mr Babbage's Calculating Machinery Mechanics Magazine 18 (488) pp. 173-75 (1832).

Babbage, C. Letter to the Editor of Mechanics Magazine, Robertson, saying that the article printed in his magazine was grossly incorrect with respect to the statements which said that he had been receiving remuneration from Government for the development of his Difference Engine and also that he had been knighted.

[Lardner, Dionysius] (1834) Babbage's Calculating Engines. The Edinburgh Review Vol. LIX No. CXX ART. Edinburgh: printed by Ballantyne and Co. for Longman ... London; and ... Black, Edinburgh, July 1834.

[ ] (1834) Mr Babbage and his Calculating Engines Mechanics Magazine 21 (578) pp. 391-2 (6 Sept 1834).

Babbage, C. (1835) Une lettre à M. Quetelet de M. Ch. Babbage rélativement à la machine à calculer Acad. Roy. Bruxelles Bulletins 2 123-6. One of the most important communications in the History of Computing; the first public announcement that he was working on the designs for a new calculating engine based on entirely different principles from those which had gone before; a machine which was later to be called the Analytical Engine. "This machine is intended to contain a hundred variables ... each of these numbers may consist of twenty-five figures; ... and [can perform] any given function which can be formed by addition, subtraction, multiplication, division, extraction of square roots, or elevation to powers."

P.S.C. (1835) Mr Babbage and His Rivals, Mechanics Magazine 23 (614) p. 119 (16th May 1835).

S.Y. (1835) Calculating Machinery Mechanics Magazine 23 (624) pp. 317-8 (25 July 1835).

Babbage, C. (1837) The Ninth Bridgewater Treatise; A fragment John Murray, London. In his will the Earl of Bridgewater left £8,000 for the publication of eight treatises which gave arguments in favour of natural religion. The many then recent discoveries of the Sciences, particularly in geology and palaeontology, had brought into doubt the Mosaic view of Creation as written in the Bible. The treatises were to aim at demonstrating that the new scientific discoveries provided clearer evidence for the existence and will of a Heavenly Designer. The eight appeared in succession soon afterwards. The writer, however, of one of treatises, William Whewell, had complained that the pursuit of science and mathematics was particularly unfavourable to the pursuit of religion. In response to this Babbage decided to write his own "Ninth" treatise posing the opposite view. In it Babbage argued strongly in favour of the proof by design argument for the existence of God, that the Creator's works were sufficient to confirm the existence of a Supreme Being and the greatest of these efforts was the creation of man in contrast to the weaker arguments provided by the Ontological and/or Metaphysical Proofs of the existence of God, and the doubts raised in the evidence of those who claimed His existence through Revelation. It was his work on the Calculating Engines which provided some of his strongest arguments and examples to back his case. In particular he saw the role of God as the great Heavenly Programmer of a deterministic Universe, and that these programs could give rise to all the observed miracles that take place here on Earth, demolishing Hume's argument for the non-existence of miracles at the same time; he illustrated how this might work using an example with the help of that portion of his calculating engine which was completed (Fragment of the Difference Engine) and which was set to calculate seemingly to follow one mathematical law for a long time and then suddenly to change to another, yet the underlying program which produced the results in both instances was the same. He had just previous to writing this book discovered the importance of the programmed conditional process as it applied to the algorithm of division and other operations in his Analytical Engine; so the book can be seen as one written in praise of this discovery. In the book he also introduces publicly for the first time details of his geological theory of isothermal surfaces or layers in the interior of the Earth and his ideas for dating using tree rings. A description of how to prepare complex diagrams using stereotypes prepared from woodcuts is also included.

The book was subtitled 'a fragment' as Babbage's original Ms for it contained a much stronger and more scathing attack on the theologians than appeared in the final copy that went to the publishers. He was advised by Lyell and Sedgwick, the famous geologists, to water down his views on these particular points. The result was so favourable that many theologians actually took up Babbage's main points in the book, much to Babbage's amusement. A second edition was published in 1838 with revisions prepared with the help of his friend, Dr. Fitton the geologist.

Babbage, C. (1837) On the Mathematical Powers of the Calculating Engine. Unpublished manuscript. First published 1973, by Brian Randell in Origins of Digital Computers pp. 17-52, Springer. (Original Ms in Museum of the History of Science, Oxford).

L. F. Ménabréa (1842) Notions sur la Machine Analytique de M. Charles Babbage Bibliothèque Universelle de Génève, 41 352-76. A paper which Babbage had intended the Italian mathematician Plana to write following his visit to Turin in November 1840, when he took details and plans for the latest developments in his Analytical Engine to a congress of Italian mathematicians and natural philosophers and to whom he gave a series of lectures on the subject. Plana, however, was unable to carry out this task, so instead he assigned the task to an up-and-coming young colleague, Ménabréa, to do it for him. This paper was the result.

Augusta Ada, Countess of Lovelace (1843) Sketch of the Analytical Engine. Translation of L.F. Ménabréa's 1842 paper with Additions Scientific Memoirs, iii (article 29) pp. 666-731, Taylor, London. The paper which provided the first public announcement in English of Babbage's new calculating engine and the theory of its operation. Contains the world's first published program, on Bernouilli numbers.

Sir Harry Nicolas (1843) Statement of the Circumstances Respecting Mr Babbage's Calculating Engines. Privately printed, London. A paper written by one of Babbage's friends detailing the history of the construction of the First Difference Engine from the point of view of Babbage's relations with the British Government and its sponsorship of the project and how they had not fulfilled their part of the bargain. Clearly illustrates how Babbage had had a raw deal.

Babbage, C. (1843) Statement of the Circumstances attending the Invention and Construction of Mr Babbage's Calculating Engines Phil Mag 23 234-5.

[ ] (1843) Addition to the Memoir of M. Menabrea on the Analytical Engine Phil Mag 23 235-9 (Sept 1843).

Babbage, C. (1847) On the Principles of Tools for Turning and Planing Metals Found in Turning and Mechanical Manipulation by Charles Holtzapffel, Vol 2 984-7 Holtzapffel, London.

A paper on the mathematics of using a lathe for turning metals. In the book it is followed by a description of some of the workshop tools Babbage had invented.

Weld, C.R. (1848) History of the Royal Society with Memoirs of the Presidents (2 Vols), J.W. Parker, London.

Weld, C.R. (1849) The Eleventh Chapter of the History of the Royal Society, Richard Clay, London. Reproduced in The Exposition of 1851 by C. Babbage.

Babbage, C. (1851) The Exposition of 1851; Or Views of the Industry, the Science, and the Government of England John Murray, London. A diatribe written in view of the fact that he had not been invited to display his only partly completed Difference Engine at the Great Exhibition, a machine which he considered exhibited the highest levels and skills of engineering the country had to that date demonstrated.

Dodd, G. (1853) The Curiosities of Industry: Calcualting and registering machines, G. Routledge, London. pp5-10.

Rosse, Lord (1854) Presidential Address Proceedings of the Royal Society 7 pp. 248-258.

C.G. Stokes et alii (1855) Report of a Committee Appointed by the Council to Examine the Calculating Machine of M. Scheutz. Proceedings of the Royal Society (London) 7 pp. 499-508. Mentions certain special features of DE1.

[ ] (1856) Articles in Knights English Cyclopaedia 1856 (a) Arts and Science Section and (b) Biography Section.

Judex Juris [James Jerwood] (1861) On the Calculation and Printing of Mathematical Tables by Machinery; the Inventor and his Treatment, [privately printed 1861]. Title and pp. 3-53.

Smiles, Samuel (1863) Charles Babbage on Joseph Clement in Industrial Biography Appendix IV p. 343.

Timbs, J. (1863) Stories of Inventors and Discoverers (2nd Edition) Lockwood and Co, London.

Waller, J.F. [editor] (1863) Entry (by JPN) on Babbage in the Imperial Dictionary of Universal Biography 1857-63.

Babbage, C. (1864) Passages from the Life of a Philosopher

Longman, Green, etc, London. Babbage's autobiography. Contains several chapters on Difference Engine No. 1.

Brewster, David (1868) Mr Babbage's Calculating Engine pp. 340-345 in Letters on Natural Magic, addressed to Sir Walter Scott, Bart. (New Edition), William Tegg, London.

Walford, C. (1871) Calculating Machines an article in The Insurance Encyclopaedia 1 pp. 411-25.

Babbage, B. Herschel (1872) Babbage's Calculating Machine; or Difference Engine. A Description of a Portion of the Machine put together in 1833 [actually 1832] and now exhibited, by permission of the Board of Works, in the Educational Division of the South Kensington Museum, Science and Art Department, London, 1872. Title and pp. 1-8 with frontispiece reproduction of the woodcut illustration of the fragment Difference Engine by B.H. Babbage. Text addressed 1 Dorset Street, dated 28th September 1872.

[R.T.] (1872) Mathematical and Scientific Library of the Late Charles Babbage ... to be Sold by Private Contract. Offers will be received up to 1st Feb. 1873. If not the disposed of, the Collection will be sold (in lots) by Auction ... Catalogues and cards to view, may be obtained from Messrs Sothebys, Wilkinson, and Hodge. Printed by C.F. Hodgson & Son, Gough Square, Fleet Street, 1872. [2590 lots listed]

Macready (????), Diaries of William Macready Vol 1 p. 409 September 17th 1837: Lardner detailed the history of Babbage's quarrel with Government about his calculating machine. It seems Governnment assisted hime with funds to the amount of £15,000 to £16,000 for the construction of the first, which he relinquished, and for a second, an improvement on the first,which he discontinued because Government had not given him the distinction and reward to which he thought himself entitled, Government said, "Finish the work, and then --" but he said to his friends that he ought not to be kept waiting till he was old, but should be remunerated now! He has subsequently discovered a still further improvement, and leaves the second (No.2) machine to Government -desiring to make a fresh bargain with them for No. 3. Professor Airey says the thing is a humbug; other scientific men say directly the contrary.

Marshall, W.P. (1879) Babbage's Calculating Machine Proceedings of the Birmingham Philosphical Society 1 pp. 33-48. Comprises a description of the operation of the 1832 fragment of DE1. Contains errors.

de Morgan, Sophie E. (1882) Memoir of Augustus de Morgan, with Selections from his letters, Longman, Green etc., London. P.89 "I well remember ...," London 1882 note on Ada's visit to see Babbage's Engine.

Babbage, Charles (Edited by Henry P. Babbage) (1889) Babbage's Calculating Engines. Being a Collection of Papers Relating to Them; their History, and Construction. London: E. and F.N. Spon, 1889. 4to, pp. viii, 342, [3] list of Babbage's papers, folding table at p. 50, halftone portrait frontispiece of Charles Babbage in oval frame (154 x 126 mm with a facsimile of his signature and "From a photograph taken in 1860", impression of a woodcut of Difference Engine, No. 1 and 14 other plates including 4 folded and a large folding "General Plan of Mr. Babbage's Great Calculating Engine".

Modern reproduction by Tomash Publishers (Reprint Series for the History of Computing).

Crosse, A. (1892) A Twilight Gossip with the Past Temple Bar 96 pp. 179-201 (Oct 1892).

Fitzgerald, W.G. (1895) The Romance of Our Museums The Strand Magazine 9, pp. 709-715.

De Morgan (1895) a letter from Lady Byron to Sophia Frend (De Morgan) 28th June 1834 on the attendance of Ada at Dr. Lardner's lecture at the Mechanics Institute on Babbage's Difference Engine.

Airy, George (1896) Autobiography of Sir George Airy (ed Wilfrid Airy) Cambridge University Press p.37:... Sketch for a computing machine (suggested by the publications relating to Babbage's), sketch of a machine for solving equations. ... [1822]. p.152: "On Sept 15th [1842] Mr Goulburn, Chancellor of the Exchequer, asked my opinion on the utility of Babbage's calculating machine, and the propriety of expending further sums of money on it. I replied, entering fully into the matter, and giving my opinion that it was worthless."

Babbage, [Henry Prevost] (1910). Memoirs and Correspondence of Major-General H.P. Babbage. London: William Clowes & Sons, n.d.. 8vo, frontispiece portrait, pp. vi, 252.

Moulton, Lord (1915) The Invention of Logarithms, Its Genesis and Growth pp. 1-24 in Napier Tercentenary Memorial Volume (e.d C.G. Knott) Longman, Green etc. London.

Ticknor, George ( ) Life and Memoir of George Ticknor: Note on seeing and a description of Difference Engine No 1.

Stokes, Sir George Gabriel ( ) Memoir and Scientific Correspondence p. 419 17/4/1886 re fate of Difference Engine

Edgeworth, Maria ( ) Letters of Maria Edgeworth

Lyell, Charles ( ) Lyell's Journal p. 361 Vol 1 Jan 6 1832 " I am writing in an unaccustomed place, the room in which Babbage's celebrated machine is constructing -Southwark; for having met him, he proposed to me to take a walk here, and has left me while he transacts business. ..."

Selection of 20th Century References and Sources

The National Register of Archives, Quality House, Quality Court, London WC2.

The journal Annals of the History of Computing.

Works of Babbage (11 vols) edited by Martin Campbell-Kelly (Pickering and Chatto, London 1989).

The Origins of Digital Computers (3rd Edition) edited by Brian Randell (Springer Verlag 1982).

Charles Babbage, Pioneer of the Computer by Anthony Hyman (Oxford 1978).

Memoir of the Life and Labour of the Late Charles Babbage by Harry Wilmot Buxton (ed. A. Hyman) (MIT press, 1988)

Ada, a Life and Legacy by Dorothy Stein (MIT press 1985)

Irascible Genius Charles Babbage, Inventor by Maboth Moseley (Hutchinson 1964).

Gentlemen of Science by Morrell and Thackray (Oxford University Press)

Gentlemen of Science: Early Correspondence (Camden Fourth Series No. 30) by Morrell and Thackray (Royal Historical Society 1984).

Georg Scheutz and the First Printing Calculator (Smithsonian Studies in History and Technology No. 36) by Uta C. Merzbach. (Smithsonian Institution Press, Washington 1977)