science · 05 February 1850 · 174 years ago
In 1850, the first U.S. patent for push-key operation for an adding machine was patented by Dubois D. Parmelee of New Paltz, N.Y. (No. 7,074). His "Calculating Machine" patent diagram showed 9 keys. The operation of any key would cause a ratchet to raise a graduated indicator rod at the rear by a corresponding number of notches. Key 2 followed by Key 4 would thus reveal a total of 6 graduations. He anticipated another form using dial indicators to count tens and hundreds. Parmelee also invented a suction socket for artificial limbs almost a century before its general use (Patent No. 37,637, 10 Feb 1863). His calculator was unsuccessful. Over 40 years later, the first practical adding machine was invented by William Burroughs.
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