Popular Science Monthly 



261 



One Horsepower Will Run All 

 the Watches in the World 



AN astute French mathematician 

 l\ has found that in certain 

 watches the motions exceed two 

 hundred million a year in little 

 equal jumps. In the same time the 

 outside of the average balance 

 travels seven thousand five hundred 

 miles. Yet despite this astonishing 

 distance traveled by the ordinary 

 watch the amount of power con- 

 sumed is trifling. One horsepower 

 is sufficient to run two hundred and 

 seventy million watches. This is 

 probably all the watches that are in 

 existence. But if there should be 

 more there would be enough power 

 left in the one horsepower to run 

 an additional thousand watches 



A self-contained motor-truck equipped with standard 

 electric street car trolley pole and a storage battery 



The Latest Conceit in Timepieces — A 

 Buttonhole Watch 



IN spite of the fact that there is no article 

 of jewelry more useful than the watch, 

 it seems hard to stow it away in a suit of 

 clothes. It has been tucked away in vest 

 pockets and belts, attached either to an 

 ornate chain or an inconspicuous ribbon, 

 and has adorned the wrists of all classes. 



But the very latest and most con- 

 spicuous location yet chosen for it is 

 in the buttonhole of a coat lapel. 

 The buttonhole watch is nec- 

 essarily tiny, and fits into 

 gun metal case which i 

 sembles a large-sized collar 

 button in shape. When 

 worn merely for the con- 

 venience of the owner 

 the watch is usually 

 turned upside down so 

 that the time may be 

 seen at a downward 

 glance, without even 

 lifting the lapel of 

 the coat. 



It is said that the 

 diminutive size of the 

 watch does not interfere 

 with the accuracy of the 

 works. The principal ob- 

 jection to wearing one of 

 them just now is that the 

 buttonhole is needed for 

 flag emblems and liberty 

 bond buttons. 



Making a Trolley-Car of the 

 Motor-Truck 



WHY can't motor-trucks and other 

 commercial vehicles obtain their 

 power from overhead trolley wires? So 

 they can, if reports from Bradford, England, 

 are true. 



In Bradford a motor-truck with a trolley 

 pole attached to its cab takes power from 

 overhead street car wires. The 

 truck runs along on the street-car 

 tracks, contact with the rails 

 being made by means of a cast- 

 iron block to the steering gear. 

 This block also steers the 

 vehicle. 



When the truck reaches 

 the end of the street-car 

 tracks, the rail con- 

 tactor is lifted, the 

 trolley pole pulled 

 down, and the stor- 

 age battery is 

 brought into action. 

 The truck then con- 

 tinues on its way as a 

 self-contained vehi- 

 cle. The motors are of 

 twenty horsepower. 

 The battery is arranged 

 so that it can be charged 

 with street car current 

 when the truck is run- 

 ning. On one charge of 

 thebattery the truck can 

 run for about ten miles. 



The buttonhole watch fits into a case 

 resembling a large-sized collar button 



