Aërodynamics: Constituting the First Volume of a Complete Work on Aërial Flight

Abstract

THE book before us is the first volume of a complete treatise on aërial flight, and is to be followed by a volume on “aërodonetics,” a word coined by the author to denote the theory of the motion and equilibrium of bodies in the air. The author, by the way, is rather fond of coining new words; some of them—aërofoil, for example—are very happily chosen, and we hope that they may be adopted by subsequent writers on the subject. So far as mathematical theory is concerned, aërodynamics as applied to problems of flight does not differ from hydrodynamics, for with the small changes of pressure that accompany the motion of a flying machine, the compressibility of the afr does not sensibly affect the motion. The first chapters, which deal with the theory of aërodynamics, are therefore a summary in non-mathematical language of the chief methods and results of hydrodynamical theory. They are, on the whole, very clearly written, and present in simple form all the most important points of the theory. The author is not, however, content to follow orthodox theory, but deviates from it in the treatment of several problems. Thus on p. 6 he introduces what he calls the “principle of no momentum,” i.e. that no resultant momentum can be communicated to a fluid enclosed in a rigid boundary. Against the principle as stated no objection can be taken; but when, as on p. 16, it is applied to the motion of a body in an. infinite fluid, it may easily lead to false results.

Aërodynamics: Constituting the First Volume of a Complete Work on Aërial Flight.

By F. W. Lanchester. (London: A. Constable and Co., Ltd., 1907.) Price 21s. net.