53o SCIENCE PROGRESS 



little that is new to say, and he leaves the deeper problems of human evolution 

 almost untouched. The descriptions of the various bone and stone implements 

 are, however, excellent, and the book deals more fully, if not more accurately, with 

 the fauna and flora than any other book in the English language. The illustra- 

 tions, which include several good maps, are also admirable. 



The story is told, as already stated, in a chronological manner. Now, as is 

 well known, human palaeontologists are divisible into two schools, which may be 

 styled the extreme and the conservative. The extreme views of such writers as 

 Profs. Keith and Rutot are not considered by Prof. Osborn worthy of discussion 

 in this popular volume. It is not, however, so generally known that the conserva- 

 tive school is itself subdivided into two subordinate classes of opinion, differing 

 from one another on the question of the geological antiquity of man in Europe. 

 All the scholars of the conservative school agree in accepting the same discoveries, 

 and in discarding an array of finds which are brought forward by the extremists ; 

 the point in dispute is the correlation of the accepted discoveries of bones and 

 implements with the glacial and interglacial ages. Prof. Osborn accepts the ultra- 

 conservative interpretation of the facts, which is that believed by most French 

 authorities, and he accordingly regards the whole of the Late Palaeolithic Period as 

 later than the Fourth (Wiirmian) Glacial Period. The other scheme is that 

 adopted by the leading German scholars, and by Prof. James Geikie and probably 

 by most English geologists, though not by Prof. Sollas. The reader should 

 remember when perusing the author's chronology that the two ingenious schemes 

 are different from beginning to end, and that they are notoriously a matter of 

 controversy. We think the author is doing a very useful service in attempting to 

 describe quite definitely the fauna of each glacial and interglacial period. The 

 time for definite statements on these points has arrived ; and it is, of course, very 

 possible that the scheme which Prof. Osborn and his eminent French colleagues 

 advocate may ultimately be proved to be the true one ; but it is unfortunate that 

 he has not always been careful to represent correctly the views of those from 

 whom he differs. For instance, the table on page 33 quite misrepresents Geikie's 

 scheme. That writer placed the Aurignacian and the Solutrean in the transition 

 time between the Third Interglacial Period and the Fourth Glacial, and regarded 

 the Magdalenian as essentially the culture of the Fourth Glacial Period. Prof. 

 Osborn makes Geikie attribute the Magdalenian entirely to post- Wiirmian times. 

 Again, the Lower Turbarian Age of Geikie, which was Neolithic, certainly does 

 not correspond with the Buhl stadium in the Alps (see pp. 361-3). It probably 

 corresponds, as Geikie believed, with the later Gschnitz stadium, but was certainly 

 not earlier. The trouble arises from the fact that Geikie makes six glacial epochs, 

 not seven, the reason being that in Scotland he could not disentangle the traces of 

 the Wiirmian and Buhlian glaciers from one another. 



A. G. Thacker. 



ENGINEERING 



Text-Book of Mechanics. Vol. VI. Thermodynamics. By Louis A. Martin, 

 Junr., Professor of Mechanics at the Stevens Institute of Technology, 

 Hoboken, N.J. [Pp. xviii + 313, with 78 figures.] (London : Chapman & 

 Hall, 1916. Price 7s. 6d. net.) 



This little text-book is intended for the use of engineering students who have no 

 previous acquaintance with thermodynamics, but who possess some knowledge 

 of the rudiments of the calculus. In its general plan it follows the usual lines, and 

 it will be much appreciated by the teacher for its numerous examples ; it contains 



