K&E 68-1400 ANALON

Produced in the United States during the last years of the Slide Rule Era, 1966 - 1970. The ANALON 68 1130 was the last model designed by Keuffel & Esser, and only one run production was made in 1967 (2), and after that, this model was discontinued.  The ANALON was only listed in K&E's 1967 catalog. It suffered from production problems, and buyers often found the instruction manual to be incomprehensible. According to former curator Uta Merzbach, the ANALON slide rule was the last model manufactured by Keuffel & Esser at its plant in Hoboken, N.J., which closed in 1970 (1). 

It is a unique device designed by Michael P. Smyth, PhD, Assistant Professor of Electrical Engineering in the University of Pennsylvania, that besides to allow users perform arithmetic operations, allows to perform the dimensional analysis of the formulas computed (2). It was fabricated from white Ivorite (Acrylonitrile Butadiene Styrene (ABS) CYCOLAC™ Resin ), a smooth, white, and long wearing plastic, with an indicator made up also with plastic, and brass-colored end pieces holding the parts together. It was designed to help engineers and scientist, teachers, and students to analyse and work dimensions and units in a simple but rigorous manner, in the following ways:

The ANALON is a one sided slide rule, with eleven scales on the main face, and a table containing the dimensional analysis of 30 quantities widely used in physics, on the back face. The dimensional analysis is performed in the MKS system. Four of the eleven are the standard numerical scales A-B and C-D, for basic arithmetic operations, the other seven are non-numerical scales, all containing the same set of 30 Physical Quantities: 

On the back face table, the above quantities are expressed as powers of the four basic quantities length, mass, time and charge, as can be seen on the above table. The non-numerical scales on the front face are labeled with the letters V and U. Two of the these non-numerical scales are identical and are labeled U and V. Other two identical scales contain the reciprocals of the 30 Physical Quantities and are labeled V-1  and U-1 . Other two identical scales contain the square roots of the Physical Quantities and are labeled V-1/2  and U-1/2 . The last non-numerical scale contains the squares of the Physical Quantities and is labeled V2 . 

Additional to its very special characteristics, the Analon is the only K&E rule that can be dated precisely, because there was only one production run in 1967, but this is not the only circumstance that makes the Analon a rarity. According with Joseph L. Soper, by that time Production Manager of the Salisbury Plant where the Analons were fabricated, almost half of this production was lost because the different solvents in the acrylic ink released stress in the surface of the Cyclolac blanks, allowing the red ink to penetrate into the cracks. This resulted in very fine cobwebs forming around each character (2). 

Mr. Soper did specified that from the 2000 rules produced in this first and only run, Over a thousand defective Analons were scrapped, dumped into a barrel heading for the landfill.  He also ads that Unfortunatelly,  the Analon was not well recived by customers. Many analons were returned to retailers with the complain that the owners could not understand the manual... the distributors could not send them back to the plant because nothing was wrong with them.. Less that 600 Analons remainded int he hands of customers...

Mr. Soper also said that when asked if he knows where the landfill these Analons are buried in he answers: I know wher the landfill is, I just don't know where to start digging!

The specimen in this collection is one of those survivors of this unique 1967 production run.

Mastering the ANALON requires not only practice as any other slide rule, but like a list of formulas, the efficient use of such list it also requires from the user a knowledge and understanding of the formulas. 

I will illustrate with to easy examples the use of the ANALON for dimensional analysis. These examples will require the basic understanding of the regular slide rule scales C-D and their reciprocals to perform multiplication and division. 

We all learn in a basic Physics course the Newton's Second Law: F = ma, The force is defines as mas times acceleration, How can we see this on the ANALON? Using the scales U and V (that are aligned to the scales C-D), Set the cursor's hairline on the  M  in scale V, and then move the slider until the left number 1 of the scale  C  is under hairline (Fig.1.a)). Move now the cursor an place the hairline on the acceleration  a  in the U-scale, dimension force  F  is under the cursor's hairline on the V-scale (Fig.1.b)

In a basic Physics course we also learn that Power is the Work performed per Time: P = W/t.  Using again scales U and V, set the cursor's hairline on the W in the V-scale, and move the slider until you set the  1  at the right o the C-scale under the hairline (Fig.2.a). Move now the cursor until set the hairline on the number  T  in the U-scale, and under the hairline you read  P  on the V-scale (Fig.2.b).

There is a more-slide-rule-efficient-way to obtain the same answer, taking the product of work  W  times the reciprocal of time  T.  Set the cursor's hairline on the  M  in scale V, and now move the cursor until you set the  1   at the right of the C- scale under the hairline (Fig.3.a). Move the cursor until the hairline is on the  T  in the U-1-scale, the hairline is also on the  P  in the V-scale (Fig3.b). 

As you can see, the operation of the dimensional scales is similar to the standard scales. Of course more complex dimensional analysis can be performed as explained in the "cryptic" ANALON's User Manual

Here is a scan of the non-easy to understand ANALON's User Manual:

Analon-UserManual.pdf

Here is a link to an interesting and illustrative article about the ANALON: "A Qualitative Analysis on a Quantitative Device":

If you are interested in learning more about the dimensional analysis concepts behind the Analon design, there is interesting article written by Cliff Frohlich: Design considerations of the Analon Slide Rule.

Click on the next link to see professional panoramic pictures of the ANALON model:

https://www.sliderulemuseum.com/KE/KE_68-1400_Analon_sn003397.jpg

References.

(1). Smithsonian. National Museum of American History. Keuffel & Esser 68-1400 Analon Simplex Slide Rule. https://americanhistory.si.edu/collections/search/object/nmah_1130714 

(2). Soper L. Joseph. K&E Salisbury Products Division Slide Rules. The Oughtred Society. First Edition 2007 (ISBN 978-0-9791477-1-5)

(3). Ron Manley. Slide Rule Site. Analon. http://www.sliderules.info/collection/10inch/070/1077-analon.htm 

(4). McCoys K&E Catalogs. Collection of pages from K&E catalogs for the AnaLon Slide Rule. https://www.mccoys-kecatalogs.com/KEModels/ke68-1400family.htm