Burroughs Built an Adding Machine That Printed, Then Smashed the First Fifty With a Window
Bank clerks added long columns by hand and had no way to check their work except doing it again. William Burroughs built a machine that printed every entry and the total. The first production run only worked for him, so he threw them out a window.

US388116 was granted to William Seward Burroughs on August 21, 1888, for a calculating machine. It printed what it added, which is the part that mattered.
Burroughs had worked as a bank clerk in Auburn, New York. The job was adding long columns of figures by hand, all day, and the working conditions gave him a specific grievance: an error anywhere in a column produces a wrong total with no indication of where it went wrong. The only remedy was to add the whole column again and hope the second attempt disagreed in a useful way.
Mechanical calculators already existed. Most of them displayed a result on dials, which solves the arithmetic and not the auditing. A dial shows you a number. It does not show you the entries that produced it.
Printing the tape
Burroughs built a key-driven machine that recorded each entry on a paper tape as it was made, then printed the total at the bottom.
That changes what the machine is for. A printed tape can be checked line by line against the source documents, filed as a record, handed to a supervisor, or produced in an audit. The clerk no longer has to trust the machine or their own memory, because the machine leaves evidence.
This is the same idea James Ritty had used a decade earlier when he made the cash register display a running total where the customer could see it. Both machines are as much about verification as calculation.
The window
The first production run went badly.
Burroughs had built the prototype himself and had, without realizing it, compensated for the machine's sensitivity with his own touch. The mechanism responded differently depending on how hard and how fast the operator pulled the handle. In his hands the machines worked. In anyone else's they gave wrong answers.
Roughly fifty units had been built. The account passed down in the company is that Burroughs had them brought to him and threw them one by one out of a second-story window of the factory.
He then designed the fix, an oil-filled dashpot that governs the speed of the operating stroke regardless of how the operator yanks the handle. The machine became insensitive to the user, which is what made it sellable.
What it became
The American Arithmometer Company, which Burroughs founded with backers in St. Louis, sold the machines to banks and businesses in large numbers and later renamed itself after him. Burroughs Corporation went on to be one of the major American business machine companies of the twentieth century, eventually merging with Sperry in 1986 to form Unisys.
Burroughs himself did not see much of it. He died in 1898 at forty-one, shortly after the machine became a commercial success.
See the original
The full text and figures of US388116 are on patents.us.
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