Popuhir Science ^lonihly 



13 



By means of a trigger which ipoves but forty inches, an aeroplane can be catapulted into the 



air with a velocity equivalent to a run of forty feet on the ground. This new invention 



advances the u^e of aeroplanes at sea far beyond anything yet achieved 



Catapulting Seaplanes from Battleships 



AFKW years ago, when the thought 

 of usnig aeroplanes in connection 

 with battleships occurred to naval 

 officers, the problem of launching was 

 sohed in a crude way by means of 

 temporary inclined platforms built on 

 the deck. Apart from the military 

 objection to such a structure, the 

 weather conditions had to be decidedly 

 favorable in order to insure a successful 

 start for a flight. At no time was it 

 considered practicable to launch the 

 flying machine while the ship was in 

 motion. The machine ran down on the 

 platform on the regulation wheels of a 

 land machine; they were not real sea- 

 planes. 



It was apparent that the Inclro- 

 acroplanc or seajilane would have to be 

 carried temporarily upon a car or truck 

 from which it could be detached at the 

 right moment and allowed to rise of its 

 own imjiulse by reason of the supporting 

 pressure of the air due to the speed 

 acquired in a short run. It was also 

 clear that the car would have to be 

 quickly accelerated to full speed within a 

 run of something like forty feet. This 

 rapidly gathered headway had to be 

 insured without jerks or jars. To this 

 end Captain Washington I. Chambers 



of our navy has de\ised a compressed-air 

 catapult, the compressed air operating a 

 piston which, in its turn, actuates a 

 wire rope traveling o^'er pulleys. A 

 movement of but forty inches on the 

 part of the piston is multiplied so as 

 to draw the car forward forty feet. 



To-day, the catapult has been so far 

 perfected by the Bureau of Construction 

 and Repair of the Na\y Department 

 that it has become a permanent feature 

 aboard the a\"iation ship U. S. S. North 

 Carolina. It is now possible to launch 

 in flight the service seaplanes while the 

 cruiser is steaming along at fair speed. 



The seaplane's motor is set going be- 

 fore the catapulting process is started. 

 In fact, the pilot docs not gi\'e the signal 

 for launching until his engine is working 

 just right. The im]>ulse a.ir for working 

 the piston is drawn right from the torpedo 

 air-supply system, and the working prcs- 

 vsure is something like three hundred 

 pounds to the square inch. B\' means of 

 a cleverly designed valve the air is. ad- 

 mitted progressively to the cylinder, ami 

 in this wa\- the desired maxinunn speed 

 is reached from zero without shock. 



In the future, our na\>-, when lumd'rcds 

 of miles from shore, will be able to send 

 its seaplanes skyward with measurable 

 indifference to the weather. 



