GO 



SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE 



VOL. 



of the burners, steam could lie supplied at a sufficient pressure to run the en- 

 gines. It was realized, however, that the conditions in flight would be very dif- 

 ferent, and that in order to protect the apparatus from the wind, some sort of 

 protecting covering would have to be devised, which would of itself introduce 

 new difficulties in providing the burners with a proper and uniform draft. 



The hull, as at first constructed, consisted of a cylindrical sheathing open in 

 front, through the rear end of which the boiler and aeolipile projected inward, 



Fig. 10. Diagram of pendulum. 



so that the air taken in at the front would ho drawn through the boiler and hearth 

 to the exclusion of lateral currents. In the first tests, however, after the hull had 

 been applied, it was impossible to secure a proper rate of combustion, nearly the 

 whole hull being filled with a bluish flame, while only a very small portion of the 

 es of combustion passed into the coils of the boiler. The remedy for this lay in 

 obtaining an increased draft, and a small slack was. therefore, arranged to carry 

 off the products of combustion. This proved inadequate, and it was only after 

 several weeks of experiment with various types of smoke-stack, and constant 

 alteration of the aeolipile, thai il was possible to make the apparatus work effi- 



