From Drawings of Baldwin Patent No. 159,244
Baldwin Machine
The figures showing below serve to register multiples of addition and subtraction which would read as the multiplier in multiplications or the quotient in division. These wheels are the type wheels N, in the [patent drawings], which serve the purpose of recording the named functions of calculation.
The means by which the type wheels of the upper row are turned through the varying degrees of rotation they receive to register the results of calculation, consists of a crank-driven, revolvable drum, marked E, which is provided with several denominational series of projectable gear teeth h, which may be made to protrude through the drum by operation of the digital setting-knobs g, situated on the outside of the drum.
These knobs, as shown in the [patent drawings], are fast to radial arms, each of which serves as one of three spokes of a half-wheel device, operating inside the drum and pivoted on the inner hub of the drum.
These half wheels marked F, in the [drawings], by means of their cam faces h¹, serve to force the gear teeth out through the face of the drum, or let them recede under the action of their springs as the knobs g, are operated forward and back in the slots x, of the drum provided for the purpose.
As will be noted from the [photographic reproduction] of the machine, these slots are notched to allow the arms extending through them to be locked in nine different radial positions, and that each of these positions are marked progressively from 0 to 9.
This arrangement allows the operator to set up numbers in the different orders by springing the setting-knobs g to the left and pulling them forward to the number desired, where it will become locked in the notch when released. This action will have forced out as many gear teeth in each order as have been set up by the knobs g in their respective orders.