Burroughs Calculating Machine

Burroughs claims a machine that registers sums and prints results. Printing, not displaying — that distinction is the commercial value of the whole device.

Add a hundred four-digit numbers by hand, twice, and compare. The errors are the product — a machine that is merely faster solves the wrong problem.

Make a ten-position wheel held by a spring pawl so it cannot rest between digits. An ambiguous digit is worse than no machine at all.

Link keys 1 to 9 to levers of increasing travel, so pressing 7 advances the wheel seven steps. The key IS the number.

Press a key hard, then gently, then very fast. The wheel overshoots, undershoots and bounces. Human hands are not a repeatable actuator.

Add a fluid or air damper so the mechanism always completes at one speed regardless of how the key was hit. This is Burroughs's decisive addition and it took him years.

Repeat the hard-soft-fast test. The registered value must be identical every time. Only now is the machine trustworthy.

Fit a single long tooth that advances the tens wheel once per units revolution. Carry is one tooth, and it is where every mechanical calculator gets hard.

Adding 1 to 999 must move four wheels from one key press. Store the carry on a spring and release it in sequence rather than driving it all directly.

Fit each register wheel with raised digits on its rim. The number is stored and printed by the same part — nothing is transcribed.

Press paper against the type wheels through a ribbon on the crank stroke. Each entry is printed as it is made, building an audit trail line by line.

Arrange the key bars so two cannot be depressed at once. An operator hitting 4 and 5 together must get a jam, not a silently wrong entry.

Run a real column through it and compare the printed tape against your hand sums. Any mismatch can be traced to a specific line — which is exactly the point.

Enter a wrong figure on purpose, then locate it from the printout alone. A machine you can audit beats a faster machine you cannot.

The patent. US 388,116, "Calculating machine", granted 21 August 1888 to William Seward Burroughs of St Louis, formerly a bank clerk in Auburn, New York. He filed his first applications in 1885 and spent years on refinement. The founding story is well attested and instructive: the first fifty machines sold were returned, because results depended on how hard the operator pulled the crank. Burroughs is said to have thrown them out of a window and started again — and the fix was the dashpot governor, which makes the stroke rate independent of the hand driving it.

Printing is the invention, not adding. Mechanical calculators existed long before — Pascal's Pascaline of 1642, Leibniz's stepped reckoner, Thomas de Colmar's Arithmomètre in production from 1851. All of them displayed a result on dials, which a clerk then copied into a ledger, reintroducing exactly the transcription errors the machine was supposed to remove. Printing the entries and the total produces a tape that can be re-checked against the source documents, so an error can be located rather than merely suspected. The machine's real product is auditability, and that is why banks bought it.

The carry is always the hard part. Any wheel-based register is trivial until a digit passes nine. Then one key press must advance two wheels, and at 999 it must advance four — all from the energy of a single finger. The general solution is to STORE the carry on a spring as each wheel passes zero and release the stored carries in sequence, rather than trying to drive the whole cascade directly. Pascal faced this in 1642 and it is still the limiting mechanism in the last mechanical calculators of the 1960s.

What became of it. The American Arithmometer Company, founded to make it, was renamed the Burroughs Adding Machine Company after his death in 1898 and became one of the largest office-equipment firms in the world; it eventually merged with Sperry — whose gyrocompass appears elsewhere in this batch — to form Unisys in 1986. Burroughs died at 41, of tuberculosis, shortly before the machine made the company's fortune. His grandson, the writer William S. Burroughs, was named for him.