CHAPTER III 



AVAILABLE MOTORS 



In the introductory chapter to " Experiments in Aerodynamics," it was 

 asserted thai 



" These researches have led to the result that mechanical sustenialion of 

 heavy bodies in the air, combined with very great speeds, is not only possible, 

 but within the reach of mechanical means we actually possess." 



It was, however, necessary to make a proper selection in order to secure 

 that source of power which is best adapted to the requirements of mechanical 

 flight. Penaud had used india rubber as the cheapest and at the same time the 

 most available motor for the toys with which he was experimenting, but when 

 models were constructed that were heavier than any t lung made prior to 1887, it 

 appeared, after the exhaustive trials with rubber referred to in the preceding 

 chapter, that something which could give longer and steadier flights must be 

 used as a motor, even for the preliminary trials, and the construction of the 

 large steam-driven model known as No. 0, and elsewhere described, was begun. 

 Even before the completion of this, the probability of its failure grew so strong 

 thai experiments were commenced with other motors, which it was hoped might 

 be consistent with a lighter construction. 



These experiments which commenced in the spring of 1892 and continued 

 for nearly a twelvemonth, were made upon (lie use of compressed air, carbonic- 

 acid gas, electricity in primary and storage batteries, and numerous other con- 

 trivances, with the result that the steam engine was finally returned to, as be- 

 ing the only one that gave any promise of immediate success in supporting a 

 machine which would teach the conditions of flighl by actual trial, though it may 

 be added that the gas engine winch was not tried at this time on account of 

 engineering difficulties, was regarded from the first as being the best in theory 

 and likely to be ultimately resorted to. All others were fundamentally too 

 heavy, and weight was always the greatest enemy. 



It is the purpose of this chapter to pass in brief review the work that was 

 done and the amount of energy that was obtained with these several types of 

 motors, as well as the obstacles which they presented to practical application 

 upon working aerodromes. 



India Rubber 

 India rubber is the source of power to which the designer of a working- 

 model naturally turns, where il is desirable that it shall be, above all, light and 

 free from the necessity of using complicated mechanism. Rubber motors were, 



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