The Diffraction of Plane Electromagnetic Waves. 505 
one exceptional set of curves, obtained at the United States Model Basin,* 
which shows two maxima: a phenomenon which has not received explana- 
tion. It is conceivable that this may be a case in which the two maxima 
indicated in the intermediate curves of the present paper have become 
prominent through some unusual features of the model. In this con- 
nection, it must be remembered that the present calculations are based 
upon a surface pressure of specially simple type, one symmetrical round a 
point; one could extend the calculations by integration, as in the previous 
results for deep water, so as to apply to a pressure distribution, giving 
a better analogy with ship form. It may be anticipated that the results 
would be of the same character in general, though no doubt better agree- 
ment could be obtained in certain details. 
* D. W. Taylor, loc. ctt., p. 115. 
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