258 SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE VOL. 27 



minutes before the model was actually launched, i! will be noted that a board 

 (.1 ) projects from the front of the launching car. This board, which is mounted 

 in a false floor of the launching car, is so arranged that when it strikes the two 

 blocks (B) at the eud of the track it is driven backward in the car against the 

 triggers which prevent the uprights (D), supporting the aerodrome, from being 

 folded down against the floor. When this hoard strikes the triggers it releases 

 them and the springs (C), which in this case were rubber bands, immediately 

 fold the vertical posts or uprights {D) against the brace posts {E), which are 

 immediately folded down flat against the floor of the car through the action of 

 the spring hinges, by which they are connected to it. These uprights (D), 

 which support the aerodrome at the front and rear, respectively, are not re- 

 leased until a fraction of a second after the release of the clutch hook (F), 

 which is attached to the middle upright (G), and which, grasping the lower 

 pyramid, holds the machine down firmly against the uprights (D) previously 

 referred to. In order to prevent the possibility of the aerodrome being re- 

 leased prematurely while the car is held at the extreme rear end of the track 

 by the hook (H), a steel pin (J), which can just be seen in the photograph, is 

 pushed through a hole in the board {A), and into a hole in a cross-member on 

 the bottom of the car, thus holding the board in its proper position. After the 

 engine is started up one of the mechanics who has assisted in starting it is 

 under orders to remove the pin at the word " Ready," and at the word " Go ' ; 

 the other mechanic who has assisted in starting the engine is under orders to 

 release the hook (H), and thus allow the car to dash down the track. In the 

 experiment on August 8 the mechanic failed to remove the pin (J) at the proper 

 time, and it was only after the machine had been released and started down 

 the track that it was seen that the pin had not been removed. It was then, 

 however, too late to stop it, so the car (lashed down the track. Although the 

 striking of the board against the blocks caused the pin to split the board to 

 pieces, the launching apparatus worked perfectly and the aerodrome started off 

 on a perfectly even keel, the propellers revolving at an exceedingly high rate 

 of speed. The aerodrome flew straight ahead for a distance of 350 feet, when 

 it began to circle towards the right, descending slightly as it circled. Upon 

 completing a quarter circle it again began to rise, flying straight ahead until 

 it had -one a similar distance, when it again lost headway, but before it reached 

 the water the engine increased its speed and the aerodrome again rose. When 

 the engine slowed down for the third time, however, the aerodrome was not many 

 Beet above the river, so that before the engine regained its normal speed the 

 aerodrome touched the water with its propellers still revolving, but very slowly. 

 While the total distance covered was only about 100Q feet, and the time that it 

 was actually in the air 27 seconds, yet in this brief time it had served the main 

 purpose for which it had been built, which was to find out if the balancing of 



