NO. 3 LANGLEY MEMOIR ON MECHANICAL ILK, ill lS.j 



A.VIATOB 's ( !aB 



In determining on a suitable car for the aviator various designs were made, 

 differing all the way from that in which the aviator occupied a sitting position 

 facing directly ahead and with practically no freedom of movement, hut was 

 even strapped to the machine to avoid I lie possibility of being thrown out, to 

 the one finally adopted, in which lie was provided with the greatesl freedom of 

 movement, could either stand or sit, as the occasion seemed to demand, and 

 could face in any direction for giving proper attention to any of the multitudi- 

 nous things which might at any lime require his attention, and could, if agile, 

 even climb from the extreme front of the machine to the rear. The wisdom 

 of giving the aviator complete freedom without hampering him in any way by 

 provisions for preventing his being thrown out of the machine was amply jus 

 titled, as will later be seen in the description of the tests of the machine, where 

 freedom of movement and agility prevented a fatal accident. 



The aviator's car- was therefore designed to occupy the entire available 

 space between the engine and the front bearing points, and between the two 

 main tubes of the main frame, thus allowing him a space of something like 

 three feet by five feet, The car itself was shaped like a flat-bottomed boat, 

 the bottom being approximately level with the bottom of the lower pyramid. 

 It had a guard rail of steel tubing eighteen inches above the floor, with a cloth 

 covering drawn over the frame to decrease the head resistance of the appurte- 

 nances of the engine which were placed at the rear end of the car. The car 

 was supported by vertical wires passing from its bottom up to the main frame, 

 and was prevented from longitudinal or side motion by being fastened at the 

 front to the cross-rod connecting the front bearing points, and at the rear to 

 the lower pyramid. A light wooden seat extended fore and aft of the car at 

 a height of about two feet from the floor, this seat resting on blocks of sponge 

 rubber to absorb some of the tremor which existed in the whole aerodrome 

 when the engine and propellers were working at high speed. The aviator was 

 thus free to stand, to sit sidewise or to straddle the seat, and while the network 

 of wires surrounding him prevented any great possibility of his being thrown 

 out, yet there was a comparatively large opening between the guy-wires pass- 

 ing overhead which permitted him to climb out of the machine. 



In order to enable the aviator to know exactly how the engine was operat- 

 ing, a tachometer, giving instantaneous readings of the number of revolutions, 

 was connected by a suitable gear to one of the transmission shafts and placed 

 where it could readily be seen. 



During 1898 and 1899 considerable time and attention had been given to 

 designing an instrument to he carried by the aerodrome which would automat- 

 ically record the number of revolutions of the engine, the velocity and direction 



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