In ancient times, Poco's had instructions glued to the cylinder and frames.  Over time, most of these have disappeared or been painted over.  Luckily, various people around the net have been able to recover some of them.  I copied these from the Briar Press web site where they were posted by Lynn Starun and Rick von Holdt.
This set of instructions were transcribed by Lynn Starun from pictures taken by Arie Koelewyn (see
Warning: Insert both ends of tympan in same side of slot

Operating Instructions for the



(a) There is a single slotted reel rod into which both ends of tympan are inserted. Be sure to insert both ends of tympan in same side of reel rod.

(b) Have the slot vertical and the crank up when placing tympan

(c) Turn reel-rod to the left with pin wrench, bracing the crank handle against the body. Ends of typan will slip for 3/4 of a turn and then bind and lock.

(d) The proper size of tympan is 28 inches long by 12 inches wide with corners cut off 4 inches down the side and 3 inches across.

(e) For 24 cents in stamps we will mail 12 tympans cut to correct size in a tube post paid. Tympans must be of right shape and size to operate successfully.

(f) In replacing an old tympan, take care to crease the curl out of the ends to facilitate insertion in reel rod.

(g) Keep the tympan tight. It stretches under use.

2. HOW TO HANDLE PACKING: First wrap all the packing except tympan into a tight roll so that it will conform to the cylinder; then with the bed centered, place all the packing on the bed in proper sequence with tympan below; then leaving the tympan lie, wrap all the rest into position on cylinder with the two hands; hold into place with the left hand spanning the cylinder opening; while the right hand brings the right end of tympan into position ; insert tympan in the reel rod slot with the aid of both thumbs while the fingers hold packing on both sides from slipping; then span cylinder opening with the right hand and bring the other end of tympan into place with the left hand; insert packing in same side of slot aided by the thumbs as before, holding both sides in place with left hand while the right tightens reel rod.

3. WHAT KINDS OF PACKING: Press is shipped with packing suitable for mixed type and half-tone forms, although the cuts should always be underlaid with 2 or 3 papers. When the proving results to type, remove some press board and substitute papers. This will also make press operate easier under impression. Always have at least one press board under tympan.

4. WHAT TO OIL: At each end of cylinder shaft and roller shaft is an oil hole, 8 in all, which should be occasionally filled.

5. WHY THE STOP PINS IN BED: At each end of bed are two pins against which a piece of furniture may be placed. These pins may be driven out from below with the reel rod pin wrench when it is found more convenient to slide a galley, or matter from a galley to bed of press.

6. WHY THE GALLEY PLATE: The galley plate is .050 inches thick, which is the standard of American galleys. Cuts and forms placed on the galley plate are the proper height. Galley plate can be removed and galley of matter placed directly on the bed. If this shows a light impression, the galley is thin and should be underlaid with paper. Forms 12 inches and less laid in galleys larger than 12 3/4 inches outside can be slid onto galley plate by placing galley plate a bit beyond the ends of bed bearers and returned in the same way.

7. SET PRESS LEVEL so that the cylinder runs free. When bed is in center position it should rock slightly on center rollers, which are higher than end rollers If not found this way, and if bed strikes on the end rollers, the frame is twisted by not setting level. Experiment by wedging under each foot (one at a time) until the bed runs free and rocks on center rollers.

8. HOW TO FEED PAPER AROUND CYLINDER: The left end of tympan goes under reel rod when taut, and acts as a gripper for feeding sheet around the cylinder. This can only be done when proving from the right side. Place paper on top of cylinder and with both hands feed the right edge around and wedge it under the reel rod. Hold loose end of sheet against cylinder with right hand while the left hand operates the crank. This method of proving gives the cleanest possible proofs.

9.HOW TO CRANK THE PRESS: To get a steady, constant printing speed when using a hard impression move bed toward cylinder until just before the form print?? and then if proving from the right side push handle with the left hand, bracing with the right hand on crank cylinder shaft, using a short rotating body movement. If proving from the left side, push handle with the right hand, bracing the left hand on crank at the bearing? , using a short rotating body movement. Pushing gives more slow power than pulling. Do not work so fast that the form slides.


A. Use good ink if you want good ???. Don’t expect a $5.00 proof from 25 cent ink.

B. The less ink the better. Reduce amount of ink on slab until it is not tacky.

C. Wash cuts off before proving.

D. Use hard packing and hard impression for half tones and solids; use medium soft packing and lighter impression for type and line cuts.

E. For quick work lay proof paper on the form. For best results feed paper around cylinder. If proof paper is too short to be gripped under reel rod lay it on the form until the front edge is caught under impression, then hold loose end of sheet against cylinder and operate as per instructions No. 8 and No. 9 This not only gives a clean proof but will avoid wrinkling of the paper with an open or ruled form.

F. Use a good firm roller free from flaws. It takes a good roller to distribute ink properly.

G. If you prove the paper flat on the form, steady it against smutting while being placed by holding one corner down first with a finger on a type high bearer or inverted cut placed along side after inking After impression curl the proof slowly from the form holding one corner firmly down as above.

H. Use type high bearers when inking cuts so that the edges of roller are on the bearers. This avoids too much ink on the outlines.

I. Use type hight bearers around cuts while taking impression. This avoids guttering and too much impression on edges of cut.

J. Apply the ink roller to the form as lightly as possible consistent with uniform distribution.

K. When proving type-forms which tend to wrinkle the proof, make packing harder with pressboard, use as heavy proof paper as permissible, reduce impression, and use more ink. The same result can be obtained by laying a piece of pressboard flat on top of proof sheet on form.

L. This is a practical machine: consult your pressman in case of trouble.

HORACE HACKER & COMPANY, Manufacturers, 312 North May Street, Chicago, Illinois

The next set of instructions were posted by Rick von Holdt

1. If press does not work freely turn screws in feet up or down as required until bed moves easy.

2. Oil rollers under bed. No oil necessary in cylinder shaft ball bearings.

3. Note how tympan is inserted in reel rod so you can put on a new one properly.

a. Additional tympans cut to proper size, prices on application.

b. Additional rubber blankets cut to size, prices on application.

Hacker Manufacturing Company

312 North May Street Chicago, Illinois
I'll note that a tympan cut according to the above instructions is too long for my cylinder.  Additionally, these instructions ignore the adjustable eccentrics on my press, suggesting that the instructions above may be for an earlier version of the press.