Plus & Sumlock Mechanical Calculators 

SUMLOCK model 912/Y/122703 ImperialWeight "Comptometer" This is a direct action keyboard calculator of the "comptometer" type with a keyboard for calculations in Imperial weight units. 330 mm x 315 mm x 135 mm (13" x 12.5" x 5.5"), 7 Kg (15.5 lbs). Manufactured about the 1950's1960's. Imperial weight units work like this: The keyboard of this machine (see below) has keys with, from the left, 7 columns of Tons keys, 2 columns for Hundredweight keys, 1 column of Quarters keys, and 2 columns for the Pounds keys. The machine in the photograph displays the total of 10 Tons, 19 Hundredweights, 3 Quarters, and 23 Pounds. 




Text & photographs copyright © 2002, 2003 Nigel Tout, except where noted otherwise. 