Sept 1896 Felt and Tarrant Comptometer: Earliest - wood-cased “Woodie” model (serial 2491) and is ranked as number 40 in the list of oldest Comptometers known to still be in existence. It is still in good working order.
Provenance: ex J M Goldman1
Patented in the USA by Dorr E. Felt in 1887, the comptometer was the first commercially successful key-driven mechanical calculator. A key-driven calculator is extremely fast because each key adds or subtracts its value to the accumulator as soon as it is pressed and a skilled operator can enter all of the digits of a number simultaneously, using as many fingers as required, making them sometimes faster to use than electronic calculators. Consequently, in specialised applications, comptometers remained in use in limited numbers into the early 1990s.2
This is the very earliest model of the comptometer and was built with a wooden case. These rare wood-cased models were built between 1887 and 1903. The earliest (including this one) had external springs on the key shafts. After that they went inside but the key pads had a circular metal rim. The serial number is 2491 out of a total production of 6250. Finally the keys were composites. This is the early version with metal rimmed keys and external springs so it is reasonable to date it as abt 1895. Consistent with this it is stamped September 96.
Jay M.Goldman of Montreal has located copies of several shoebox-era documents including the invaluable H-model Repair manual published in 1919. His collection includes (as of early 2001) one of each shoebox model except a “B” as well as a number of other early 20th century calculating machines.3
1 see http://members.cruzio.com/~vagabond/Wooden.html. see also http://www.jmgoldman.com/ (↑)
2 Text here from Wikipedia. (↑)
3 http://www2.cruzio.com/~vagabond/Credits.html] Milgram and Company. His email is old_calculators@videotron.ca (↑)
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