58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. "Jl 



SUMMARY 



1. An important part of the atmosphere, that extends for many 

 miles beyond the reach of sounding balloons, has up to the present 

 time been considered inaccessible. Data of great value in meteor- 

 ology and in solar physics could be obtained by recording instruments 

 sent into this region. 



2. The rocket, in principle, is ideally suited for reaching high alti- 

 tudes, in that it carries apparatus without jar, and does not depend 

 upon the presence of air for propulsion. A new form* of rocket 

 apparatus, which embodies a number of improvements over the 

 common form, is described in the present paper. 



3. A theoretical treatment of the rocket principle shows that, if 

 the velocity of expulsion of the gases were considerably increased 

 and the ratio of propellant material to the entire rocket were also 

 increased, a tremendous increase in range would result, from the 

 fact that these two quantities enter exponentially in the expression 

 for the initial mass of the rocket necessary to raise a given mass to a 

 given height. 



4. Experiments with ordinary rockets show that the efficiency of 

 such rockets is of the order of 2 per cent, and the velocity of ejection 

 of the gases, 1,000 ft. /sec. For small rockets the values are slightly 

 less. 



With a special type of steel chamber and nozzle, an efficiency has 

 been obtained with smokeless powder of over 64 per cent (higher 

 than that of any heat engine ever before tested) ; and a velocity of 

 nearly 8,000 ft. /sec, which is the highest velocity so far obtained in 

 any way except in electrical discharge work. 



5. Experiments were repeated with the same chambers in vacuo, 

 which demonstrated that the high velocity of the ejected gases was 

 a real velocity and not merely an effect of reaction against the air. 

 In fact, experiments performed at pressures such as probably exist 

 at an altitude of 30 miles gave velocities even higher than those 

 obtained in air at atmospheric pressure, the increase in velocity prob- 

 ably being due to a difference in ignition. Results of the experiments 

 indicate also that this velocity could be exceeded, with a modified 

 form of apparatus. 



