I 



Hill in San Francisco 



N one of the residential sections of San 

 Francisco is a hill so steep that an 

 ordinary trolley car can not climb it. 

 The chief engineer adopted a principle 

 made familiar by many mountain rail- 

 ways. A channel 

 was cut between 

 the rails of each 

 track from the base 

 of the hill to the 

 summit. In each 

 channel was placed 

 a heavy steel cable, 

 which travels over 

 a huge pulley at a 

 point where the two 



Popular Science Monthly 411 



Street-Cars Pull Each Other Up This Device Won't Let Your 



Hat Blow Off 



^TEW hats have a way of blowing off 

 i their owners' heads largely because 

 no two heads are shaped exactly alike, 

 and until the hat has been worn long 

 enough to conform to its owner's head it 

 will not fit properly. 

 A simple device 

 has been invented 

 to make any hat 

 conform to the 

 wearer's head. It 

 is an open-ended 

 tube of cloth made 

 of a single strip of 

 material. The tube 

 contains a strip of 

 sprin g-steel , one end 

 of which is doubled 

 back while the op- 

 posite end extends 

 beyond the cloth 

 tube. When the 

 device is in use this 

 is inserted in the 

 other end of the 

 tube, thus closing 

 the conformer in 

 the hat. 



The metal strip 

 has needle-like pro- 

 jections which are 

 stuck through the 

 cloth tube. These 

 serve to keep the cloth attached to the 

 metal strip and may be pushed through 

 the hat crown to keep the device in place. 

 The finishing touch is an elastic cord 

 which is used to tie the ends of the tube 

 together. 



By means of this cord the hat is made 

 adjustable to fit the head even when the 

 wearer has just received an inordinate 

 amount of unexpected praise. 

 Its elasticity will take care 

 of any ordinary expan- 

 sion, but it may be 

 untied and loosened 

 up on special oc- 

 casions. 



A hat so equipped 

 will be as stationary 

 on the motorist's 

 head as the approved 

 peaked cap and 

 equally as defiant of 

 the wind. . 



Too steep for cars to climb. The diagram 

 shows how one car pulls the other up 



tracks meet and become one at the 

 summit. 



The car at the top of the hill and the 

 car at the bottom each pick up the cable. 

 The car at the top of the hill is per- 

 mitted to run under its own power 

 down the slope, thus furnishing the 

 energy necessary to pull the other car up 

 the hill on the opposite track. 

 Compressed air is used to 

 retard the cars when 

 necessary and to pre- 

 vent a runaway 

 should a cable 

 break, which is not 

 probable. 



The solving of 

 this problem has 

 placed at the dis- 

 posal of homeseek- 

 ers a delightful 

 section of the city 

 for residences. 



A simple device which may be attached 

 to any hat to make it conform closely 

 to the shape of the wearer's head 



