406.
LAMB'S HYDRODYNAMICS. [Nature, Vol. xcvn. p. 318, 1916.]
THAT this work should have already reached a fourth edition spes for the study of mathematical physics. By far the greater part < entirely beyond the range of the books available a generation ago. 1 improvement in the style is as conspicuous as the extension of the My thoughts naturally go back to the books in current use at Cambr the early sixties. With rare exceptions, such as the notable one of S Conic Sections and one or two of Boole's books, they were arid in the e with scarcely a reference to the history of the subject treated, or aninc to the reader of how he might pursue his study of it. At the presei we have excellent books in English on most branches of mathematical and certainly on many relating to pure mathematics.
The progressive development of his subject is often an embarrassi the writer of a text-book. Prof. Lamb remarks that his " work has L tensions than ever to be regarded as a complete account of the scien< which it deals. The subject has of late attracted increased atten various countries, and it has become correspondingly difficult to do ju the growing literature. Some memoirs deal chiefly with questions of matical method and so fall outside the scope of this book; others physically important hardly admit of a condensed analysis; others owing to the multiplicity of publications, may unfortunately have bee looked. And there is, I am afraid, the inevitable personal equation author, which leads him to take a greater interest in some branches subject than in others."
Most readers will be of opinion that the author has held the fairly. Formal proofs of " existence theorems " are excluded. Some o though demanded by the upholders of mathematical rigour, tell us on we knew before, as Kelvin- used to say. Take, for example, the exist a possible stationary temperature within a solid when the temperatur* surface is arbitrarily given. A physicist feels that nothing can make t clearer or more certain. What is strange is that there should be so gap. between his intuition and the* lines of argument necessary to sat: pure mathematician. Apart from this question it may be said that where the mathematical foundation is well and truly laid, and that i few cases the author's formulations will be found the most convenient se have only the one curvature to deal with. For this curvature