MILITARY AERONAUTICS- -SQUIER. 133 



The total lifting power of this airship is 1,350 pounds, of \Yhich 

 500 ix)iinds are available for passengers, ballast, fuel, etc. At its 

 official trials a speed of 19.61 miles per hour was attained over a 

 measured course, and an endurance run lasting two hours, during 

 which 70 per cent of the maximum speed was maintained. 



Dirigible No. 1, as this airship has been named, has already served 

 a very important purpose in initiating officers of the Signal Corps 

 in the construction and operation of a dirigible balloon. With the 

 experience now acquired the United States Government is in a posi- 

 tion to proceed with the construction and operation of an airship 

 worthy of comparison with any now" in existence, but any efforts in 

 this direction must await the action of Congress in providing the 

 necessary funds. * * * 



II. Aviation. 



This division comprises all those forms of heavier-than-air flying 

 machines which depend for their support upon the dynamic reaction 

 of the atmosphere. There are several subdivisions of this class de- 

 pendent upon the particular principle of operation. Among these 

 may be mentioned the aeroplane, orthopter, helicopter, etc. The only 

 one of these that has been sufficiently developed at present to cany 

 a man in practical flight is the aeroplane. There have been a large 

 number of types of aeroplanes tested wdth more or less success, and 

 of these the following are selected for illustration. 



REPRESENTATIVE AEROPLANES OF VARIOUS TYPES. 

 The Wright Brothers' Aeroplane. 



The general conditions under which the Wright machine was built 

 for the Government w'ere that it should develop a speed of at least 

 3G miles per hour and in its trial flights remain continuousl)^ in the 

 air for at least one hour. It was designed to carry two persons hav- 

 ing a combined weight of 350 pounds, and also sufficient fuel for a 

 flight of 125 miles. The trials at Fort Myer, Virginia, in September 

 of 1908, indicated that the machine was able to fulfill the require- 

 ments of the government specifications. 



The aeroplane has two superposed main surfaces feet apart, Avilh 

 a spread of 40 feet and a distance of G^ feet from front to rear. The 

 area of this double supporting surface is about 500 square feet. The 

 surfaces are so constructed that their extremities may be warped at 

 the will of the operator. 



A horizontal rudder of two superposed plane surfaces about 15 

 feet long and 3 feet wide is placed in front of the main surfaces. 

 Behind the main planes is a vertical rudder formed of two surfaces 



