That Wonderful Watch in Your Pocket 



It breathes, and its heart beats like that of a human being 

 By John J. Bowman 



OPEN the back of your watch-case and 

 look at the "works" — more correctly, 

 at the movement. The mechanism 

 seems complicated. And so it is. There 

 are in the average watch movement about 

 one hundred and 

 fifty separate 

 parts. Many of 

 these, to be sure, 

 do not take an 

 active part in 

 the running of 

 the watch, but 

 simply con- 

 stitute a frame- 

 work, providing 

 bearings for the 

 moving parts. 



Look into the 

 watch when it is 

 going, and you 

 will see one large 

 wheel-like part 

 which is in ver>' 

 rapid motion, 



"beating" in alternate directions. 

 This is the balance. It is the 

 balance that does the actual time- 

 keeping. The rest of the machinery 

 is required (i) to keep the balance 

 in motion, and (2) to 

 make the rate of motion 

 visible as "time-keeping" 

 on the dial of the watch. 



The balance is the gov- 

 ernor; its function is comparable 

 with that'of the pendulum in a 

 clock. ' - 



One of the illustrations shows a 

 watch with part of the framework 

 removed. - The balance may be seen 

 at the top of the picture. We will 

 examine its construction in detail 

 later on, and we shall see some 

 wonders it performs in its cease- 



The mainspring 

 "barrel" 

 Winding the watch wraps the 

 mainspring around the cen- 

 tral hub in the barrel. The 

 effort of the spring is now 

 to unwind itself. This effort 

 of the mainspring causes the 

 rotation of the barrel 



DIAL-TRAINS. HANDS 

 MAKES BALANCE' 

 TIMEKEEPING 

 VISIBLE 



the center of the watch. This center wheel 

 in turn drives the pinion fastened to the 

 next wheel, and so on. Thus the power 

 is carried to the escapement. 



What Makes a Watch "Tick " ? 



The purpose of the escapement is to 

 apply a little 

 power to the 

 balance at each 

 beat of the latter, 

 to keep it in mo- 

 tion. . It is the 

 action of the es- 

 capement which is 

 heard as the "tick- 

 ing" of the watch. 

 Of course the pow- 

 er, as it comes 

 down from one 

 wheel to another, 

 turns each wheel 

 constantly in one 

 direction; but the 

 escapement is so 

 made as to apply the power 

 to the balance first in one 

 direction, and then in the 

 opposite direction, since the 

 balance must make its beats 

 in alternate directions. In 

 the past three centuries, 

 men of highest scientific 

 and mechanical genius have 

 applied themselves to the 

 problem of perfecting the 

 escapement, which is the 

 most complicated part of 

 the watch. 



A watch is simply a ma- 

 chine for "making motion" 

 — and the supreme wonder 

 of a good watch is its uni- 

 form rate of motion. Bear- 

 ing all of this in mind, it is 

 easy to understand what 



delicate balance 

 wheel 

 The balance rim of brass- 

 steel, is cut into two por- 

 tions, for expansion and 

 contraction, to suit the 

 temperature. Each end is 

 free to move inward or out- 

 ward, toward or from center 



MAINSPRING IN BARREL 

 STORAGE Of PO*ER 



BALANCE 

 CONTROLS ENTIRE 

 MECHANISM--KEEPS 

 TIME" 



Analysis of the watch 

 mechanism 



less round of duty. The gear cat -' 



wheels and pinions shown carry ^ ^^^^"^ °^ ^'^''1' 5°""'" t^'" t was mentioned in the begin 



^ , , , 1 mamspnng barrel down through . r ^1 • ^- 1 ^1 ^^l 



power to move the balance, the the train and escapement to be nmgot this article, that the 



source of power of course being consumed in keeping the works balance, which controls the 



the mainspring. >" motion. The parts (above) 



The crenr-tppth nn thp barrel ^'"^ arranged in a straight line. 



1 ne gear-teetn on tne Darrei j^^ ^ ^^^^^ however, they are 



drive a pinion fastened to the jn a curved line to park them 



shaft of the large gear-wheel in into the smallest space possible 



7«1 



rate of motion of the entire 

 watch mechanism, is es- 

 sentially the time-keeping 

 part of the watch. The 



