William S. Burroughs’ invention resembled more of a studded chest with a crank handle than the calculators of today. It was not pretty, but did relieve him from the tedium and monotony of adding up columns of numbers all day at this bank clerk job. Burroughs was more interested in mechanical engineering anyway, and soon left his bank job to open up a machine shop in St. Louis. With the freedom to pursue his dream and all the tools needed at this disposal, he created the marketable version of his machine.

On this day, August 21, in 1888, William Burroughs patented his adding and listing machine, improving on earlier designs that gave out differing answers depending on how much force was used in the pulling of the handle to perform the calculation. Listing price was $475 (around $11,300 today).

Burroughs’s “dash-pot” regulation mechanism for machine handles made his adding machine more precise than the earlier ones, but still took a certain knack to use, and so were hardly popular. By 1892 he patented an improved version that could be operated by anyone, and that came with an attached printer. Burroughs’ company eventually merged with another to form Unisys.