Mechanical counter
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Mechanical counters are counters built using mechanical components. They typically consist of a series of disks mounted on an axle, with the digits zero through nine marked on their edge. The right mo
Several mechanical counters
Mechanical counter wheels showing both sides. The bump on the wheel shown at the top engages the ratchet on the wheel below every turn.
Early IBM tabulating machine using mechanical counters
Arithmometer
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The arithmometer was the first digital mechanical calculator strong and reliable enough to be used daily in an office environment. This calculator could add and subtract two numbers directly and perfo
Mechanical counter
…Odometers Arithmometer Babbage's difference engine and analytical engine…
Arithmomètre built by Louis Payen around 1887
Detail of an arithmometer built before 1851. The one-digit multiplier cursor (ivory top) is the leftmost cursor
One of the first machines with a unique serial number (10-digit machines with serial numbers from 500 to 549) built around 1863
Front panel of a Thomas arithmometer with its movable result carriage extended