THE increasing study of science in schools has been the cause of a considerable crop of text-books of elementary physics, but there is still the want of a more advanced book on the subject. This want Mr. R. H. Jude has endeavoured to supply, and as far as can be judged by a glance through his book, supplemented by a more careful examination of a few chapters, he has succeeded in giving us what promises to be a very useful work both to teachers and students. Experience only can show whether he has hit on the right standard of difficulty, and whether the learner will find the explanations sufficiently clear and complete; but there seems no reason to doubt it, considering that the work is an English adaptation of a book by Prof. Gossin, which is apparently much used in France. Physics, Experimental and Theoretical. By R. H. Jude H. Gossin. Pp. xiii + 926. (London: Chapman and Hall, Ltd., 1899.)