G. B. Grant—New Calculating Machine. 281 
mon to all the wheels, and is ordinarily up out of the way of 
the pins, but when pressed down will be in their path. If then 
the cylinder be turned backward, each pin will stop when it 
reaches the bar, and all the wheels will be brought to zero 
simultaneously. a8 
The process by this machine is always an addition, never a 
subtraction. But subtraction of any number is accomplished 
y setting it up by the inner row of figures on  Hsgraed 
wheel, they being so arranged that the complement of the num- 
ber set up will be used. oy 3 so 
_ The size of the machine varies with its capacity. The record- 
um 11 inches and the adding wheels 24 inches in 
diameter, and the. distance from wheel to wheel is sap are 
of h ten-wheel machine would occupy a box 6x 6x 
