Jeffers Adding Machine

This U.S. patent model for a lever-set non-printing adding machine has a frame of two brown round end pieces joined by a central shaft and by two pieces of brass at the outside. The shaft carries six toothed wheels that may be rotated with the fingers. Each wheel has 30 teeth and is joined to a brass ring on its right. Around the rim of each ring is a slip of paper with the digits from 0 to 9 printed on it three times. One third of each ring is covered by a metal piece which has a window at the bottom and the digits from 1 to 9 engraved on it. To enter digits, wheels are rotated forward the distance indicated by these digits. Through the action of a carry mechanism, the total appears in the windows.

Milton C. Jeffers, who took out this patent in 1863, was a resident of New York, N.Y. He is probably the Milton C. Jeffers who lived from about 1823 until dying in New York City in 1896, and who took out two further patents for agricultural machinery. A Milton C. Jeffers is listed in New York City directories of the period as an agent and as a broker.

References:

U.S. Patent 40,105, September 29, 1863.

U.S. Patent 74,379, February 11, 1868.

U.S. Patent 108,484, October 18, 1870.

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