George L. O. Davidson, an English engineer, a year or two ago designed a bird-like machine, to be built of steel, and to sail along with spread wings, on the principle of a Lilienthal soaring apparatus, but I have never learned that the machine got beyond the stage of being represented in drawings.
This article would not be complete without a reference to Prof. S. P. Langley's aerodome, shown in Fig. 15. It has, however, been described so fully that it is only necessary to refer to it here.
The conclusion may be fairly drawn from these brief descriptions of experiments in aerial navigation, that the aerodrome is supplanting the balloon, but that it can not as yet be used alone successfully. All the flying machines that depend solely upon a motive power and supporting planes are unable to carry any large supply of fuel, and descend after a short flight. The balloon can remain in the air a long time, but it is unwieldy. The practical inference is that some combination of the balloon and the aeroplane is necessary to produce a machine that will be of commercial use in aerial navigation.
