The wing section given in Fig. 57 is that of a herring gull (Larus argentatus). The dotted line gives the form as plotted from templates made shortly after the bird had been killed; the full line gives the approximate form in flight when sustaining the weight of the bird. The direction of flight is supposed horizontal.
§ 108. Historical.—Historically, so far as the author has been
able to ascertain, the credit of the discovery of the dipping edge
is due to Horatio Frederick Phillips, whose publication is to be
found in the specification of Patent 13,768 of 1884.
Fig. 57. The discovery
appears to have been made as a matter of practical experience,
and, as often takes place under these circumstances, the theory given
by the inventor in his specification is erroneous. Just, however, as
in patent law an inventor's theory, however unsound, is not held
to invalidate an invention, so in the matter of discovery, the fact
that a discoverer does not fully understand the fact that he has
been the first to ascertain, does not in any way detract from the
credit due. In a case such as the present the fact that the
discovery is based on practical experience in the face of an
imperfect and in reality hostile theory adds rather than otherwise
to its value.
Fig. 58 is a reproduction of the forms of wing section given (as applied to artificial flight) in the specification cited. The motion
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