[30] Weights and dimensions are here given in approximate pounds and feet.
“Experiments in Aerodynamics.”
[32] On the data of “Aerodynamics,” a plane having 1.8 sq. ft. of surface per pound, and advancing at an angle of 20°, would soar at a speed of 24.1 ft. per second.
[33] It will be remembered that the purely theoretical conclusions just cited apply to the power delivered in direct thrust, but that of the above actual H. P. an indefinite amount was lost in friction and slip of propellers.
[34] It may be observed that at this time the position of the CP was calculated on the assumption that the pressure for flight surfaces was proportional to the areas, without also allowing for the fact that the following surfaces, like the tail, were under the “lee” of the wind and so far less efficient. It follows, then, that the value CP−CG was not really 0, as was assumed, but something considerable.
[35] Very exact accuracy in these minute details is indispensable to the efficient working of the engines.
[36] The reader who may care to note the evolution of this boiler, by trial and error, will find a portion of the many discarded types shown in Plate [13].