Popular Science Monthly 



427 



Another Inventor Renders a Service 

 to Humanity 



CONSIDER the picture on our right. 

 In it we see a gearing-up attachment 

 for a bicycle. It consists of a Y-shaped 

 steel forging affixed at its three ends to the 

 bicycle's frame. At its center revolve two 

 sprocket wheels mounted on the same 

 shaft. Over the smaller runs a chain r 

 from the pedal sprocket, and from the 

 larger another chain 

 goes to the sprocket 

 on the rear hub. The 

 net result is to gear up 

 the machine. 



The attachment is 

 supposed to increase a 

 rider's speed by one- 

 third, though lessening 

 the former number of 

 pedal revolutions 

 required by one-half. 

 But what about the 

 immensely greater 

 pushes on the pedals 

 necessary? Such a 

 contrivance may be useful on level boule- 

 vards. But even a small hill would put 

 it out of business. 



has a cylinder containing a cartridge and 

 firing mechanism, with a fiat plate pro- 

 jecting from the side and taking the part 

 of the trigger. When the gopher comes 

 burrowing along, shoving fresh dirt ahead 

 of him, he touches off the trigger, and the 

 gun goes off. This is hard on the animal, 

 but affords keen pleasure to the boy who 

 has sat by the mouth of the fresh 

 burrow and waited for the wily 

 gopher to make its appearance. 



THE li 

 airp] 



New attachment 

 It also "gears up' 



to gear up a bicycle, 

 the work you must do 



Making the Pesky Gopher 

 Commit Suicide 



CALIFORNIA and other western 

 states have two sorts of game that 

 are always in season. One is the gopher, 

 which is not a turtle, as he is in the 

 South, but a burrowing pest; the other 

 is the ground squirrel. Both are nuisances, 

 and both are under 

 the sentence of death 

 when it can be executed. 

 To help in carrying out 

 that sentence, a west- 

 ern inventor has worked 

 out a burrow gun. It 



Firing 

 Pin 



^;j0^ 



Pushing the dirt ahead of him, the gopher 

 sets off the trigger and shoots himself 



Cutting Dow^n 

 Engine Weight 



lighter an 

 ilane is 

 the faster will it 

 fly and the farther 

 it will go. Hence 

 the lighter the en- 

 gine is the more 

 successful will the 

 airplane be. The 

 one follows from 

 the o t h er . In 

 the development 

 of the airplane motor into the remarka- 

 ble machine it is to-day, this "weight 

 efficiency" has become very high. It is 

 little known how important was the 

 part played in the development by a 

 most simple device, originally invented 

 for preventing the escape of gas from 

 a breech-loading gun. This device is a 

 cup-shaped piece of metal, now attached 

 merely to the ends of the pistons of the 

 airplane motor. Like its use in the gun, 

 it checks the escape of the expanding 

 gases. The greater the pressure of an 

 explosion in the engine 

 cylinders, the harder 

 will the edges of the 

 metal cup be pressed 

 against the walls of the 

 cylinders. Hence the 

 less chance will there be 

 of the gases leaking 

 around the sides of the piston. 

 The power in every portion of 

 the exploding gases is therefore 

 used, and none seeps away. 



Wait until we get to transmit- 

 ting powerto airplanes wirelessly ! 

 Then a light electric-motor of 

 great power can be used. New 

 fields will open. 



Open pos- ,<■ 

 Trip Plate->| ition for \\ 

 Compression re-loading^\ 

 Spring J> /rriqger 



BlanK^ Discharge' 

 Cartridge Opening 



