Hand-held Calculator
In 1886, Burroughs and several St. Louis businessmen formed the Arithmometer Co. of America to market the machine. The first machine, however, required a special knack in pulling the handle to execute the calculation correctly. More often than not, novice users would get wildly differing sums depending on the vigour with which they used the invention. In 1893, Burroughs received a patient for an improved calculating machine, which incorporated an oil-filled ‘dashpot,’ a hydraulic governor. This device enabled the machine to operate properly, regardless of the manner in which the handle might be pulled.
