Marchant Model ACT10M Calculating Machine

This full-keyboard non-printing electric proportional gear calculating machine has a metal case painted dark green and ten columns of green and white plastic keys. A maroon tabulator set key is at the bottom of each column. These keys are numbered from 1 on the right to 10 on the left. The underlying keyboard is gold. Between banks of keys are metal rods for decimal markers.

Right of the number keys are auto divide and stop keys, subtraction and addition bars, shift keys for use in multiplication, and a reverse key. In front of these are clearance keys for the tab set and the dials. Right of these is a column of ten black keys for automatic multiplication and two carriage shift keys. Above the number keys is a row of ten windows to show a number set up (the decimal markers extend from between the number keys to between these windows).

Behind the entry register is a movable carriage with an 20-window result register and an 11-window revolution register. Decimal markers slide above the registers on the carriage. Numbers are represented by the rotation of sets of gears on three shafts under the carriage. The machine has four rubber feet. The motor at the back of the machine is inside the case and attaches to a frayed green rubber cord.

A tag on the bottom of the machine reads: ACT10M-253420. A mark on the sides and on the cord reads: MARCHANT. A paper tag glued to the base of the machine reads: Manufactured by (/) MARCHANT CALCULATING MACHINE COMPANY, Inc. (/) OAKLAND, CALIFORNIA, U.S.A. (/) This machine is manufactured under one or more of the following United (/) States and Foreign patents: (/) United States Patent 1858397 [...] 2428206. It also reads:; SILENT SPEED. Only the first and last U.S. patents recorded. Tag also mentions a 1942 Canadian patent and others.

Compare to Harold T. Avery’s 1940 patents 2,216,659, 2,211,736, and 2,217,195. The model ACT10M apparently was produced from 1941 until 1949. Patent 2428206 was issued in 1948.

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