Brunsviga Model A Calculating Machine

This lever-set pinwheel non-printing and manually operated calculating machine has a steel casing painted black, a steel mechanism, and nine levers for entering numbers. A small metal lever is at the top left of the machine. A steel crank with a wooden handle that extends from the right side of the machine rotates backward (clockwise) for addition and multiplication and forward (counterclockwise) for subtraction and division.

At the front of the machine is a movable carriage with 18 windows that show dials of the result register on the right and ten windows for the revolution register on the left. The revolution register has no carry mechanism. Digits in this register are white for additions and red for subtractions. The carriage has holes for decimal markers, but no decimal markers are present. Depressing a lever at the front of the machine releases the carriage for shifting. A wing nut on the left side of the carriage zeros the result register. The zeroing mechanism for the result register extends from the right side of the carriage, but is broken. A bell on the left end of the carriage rings when the result passes through zero.

The machine rests on a wooden base, but the lid of the case is missing.

Three marks on the front of the machine read: BRUNSVIGA, No 6384, and G.N.&C.C.a.A. a mark on the left side reads: Grimme, Natalis & Co.(/) Braunschweig - Brunswick (/) System W.T. Odhner (/) Patentirt in: (/) Deutschland (/) England (/) Osterreich (/) Ungaren (/) Frankreich (/) V.St.v.Nord-Amerika (/) Schweiz [. . .] 4578.

This example is from the collection of Felt & Tarrant Manufacturing Company.

Reference:

E. Martin, The Calculating Machines (Die Rechenmaschinen), trans. P. A. Kidwell and M. R. Williams, Cambridge: MIT Press, 1992, pp. 109–113.

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