The Arithmometer. S3 



arranged that when the button is placed, at any given 

 number, the pinion will be opposite a part of the drum 

 presenting that particular number of teeth. This whole 

 combination of mechanism is repeated as many times as 

 there are slots, and all the drums are connected by bevel 

 wheels of equal size to a horizontal shaft, which is actuated 

 by the handle b. The plate B B, which is usually termed 

 the " slide," is movable upon an elongated bar hinge at the 

 back, which permits longitudinal sliding as well as the 

 ordinary hinge action. In this plate there are a series of 

 openings c, having revolving discs beneath, each bearing the 

 numbers from to 9. To each disc is attached a bevel 

 wheel, which gears with an equal bevel wheel on one of the 

 square steel axes previously mentioned. Hence each of the 

 result discs, as they are termed, will be moved through as many 

 tenths of a revolution at each revolution of the handle as is 

 expressed by the number opposite which the corresponding 

 button is placed, and by means of a simple reversing arrange- 

 ment, actuated by the "regulator" JE, this motionmay be caused 

 to increase or reduce the numbers exhibited by the " result " 

 discs. Thus, at each turn of the handle the number " set 

 on " the buttons is added to or deducted from that previously 

 exhibited by the result discs. But in order that this 

 operation may be continued indefinitely, it is requisite to 

 provide for " carrying," and this is done by means of an 

 exceedingly elegant system of levers and cams, which come 

 into action whenever the number passes beneath any of 

 the result openings. Thus, with the instrument set as in 

 the diagram, if the handle were turned once the right hand 

 or unit result disc would move through five-tenths of a 

 revolution, and would then present the number 0. The 

 carrying mechanism would thus be brought into action, 

 and would cause the tens result disc to move through one- 

 tenth of a revolution more than it otherwise would, so as 

 in the present case to exhibit the number 4, instead of 3, 

 to which the tens button is set. 



The discs d, are known as the "quotient," from their use 

 when dividing, and simply record the number of revolutions 

 of the handle, one of the quotient discs only, viz. that nearest 

 to the unit button, being in action at one time. Thus, in 

 the diagram, it is evident that the handle has been turned 

 three times with the slide in the position shown, eight 

 times with the slide moved one figure to the right, and 

 so on. 



G 2 



