Mercedes-Euklid Model 1 Calculating Machine

The Mercedes-Euklid calculating machine has a distinctive mechanism. Moving a lever or pushing a key engages a toothed gear with one of a series of ten parallel toothed racks that move crosswise when the crank is turned. The amount a rack moves varies according to its distance from the back rack. A rod, called a proportional rod, pivoted along this rack controls this motion. The amount a rack moves determines the motion of gears linked to it, and hence the number entered.

This manually operated and lever-set proportional rod calculating machine has a black steel frame and a steel base. Nine levers are used to set numbers, with a row of windows below that shows the number set. To the right of the levers is the operating crank. In front is a carriage that can be moved when a release button to the left of the setting levers is pushed. The carriage has eight numeral wheels for recording revolutions of the crank, and 16 numeral wheels for recording results. The numeral wheels are covered with glass.

Numbers also may be set in the result register by rotating thumbscrews in the front of the carriage. They are used to set a dividend. Below the thumbscrews are knobs for zeroing the revolution counter and result register. To the left of the setting levers and carriage release button are two levers. One may be set at N or C. When it is set at N, the number in the revolution register increases by one whenever the crank is rotated. When it is at C, one rotation leads to subtraction in the revolution register. The other lever may be set at ADD.MULT or SUBT.DIV., depending on the arithmetic operation desired.

A mark on the top of the machine reads: MERCEDES-EUKLID. The serial number, given below the carriage at the left, is 1020. A mark on the carriage reads: MERCEDES-BUREAU-MASCHINEN-GES.m.b.H. [/] MEHLIS i.TH.u.BERLIN W.

Christian Hamann of Berlin patented this machine, and it was manufactured in Germany from about 1905. This example came from the collection of Felt & Tarrant Manufacturing Company.

References:

C. Hamann, "Calculating Machine," U.S. Patent 1,011,617, December 12, 1911.

E. Martin, The Calculating Machines (Die Rechenmaschinen), trans. P. A. Kidwell and M. R. Williams, Cambridge: MIT Press, 1992, pp. 156–164.

E. M. Horsburgh, ed., Handbook of the Napier Tercentenary Celebration of Modern Instruments and Methods of Calculation, Edinburgh: G. Bell & Sons, 1914, pp. 104–117.

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