The five years that have passed since the appearance of the first edition of this book (reviewed in the Journal of Glaciology, Vol. 3, No. 25, 1959, p. 432−34) have seen a considerable increase in the effort devoted to geophysical research, and this is reflected in an increase in its size from 280 to 362 pages, with a more than proportionate increase in the number of diagrams. The new material, as might be expected, comes mainly from the rapidly expanding field of marine geophysics, although references to all parts of the literature have been brought up to date. As with the first edition, the bibliography includes many papers by Russian and German authors which may be unfamiliar to English-speaking readers, and a book of this kind is all the more valuable for drawing attention to them. This exoticism, however, sometimes leads to the more standard work being given barely adequate treatment (the reviewer finds this true of the section on palaeomagnetism, and specialists in other fields might well make similar complaints) or even to the inclusion (for example, on p. 268) of hypotheses of marginal importance apparently for no other reason than to give the author the pleasure of demolishing them. He would presumably argue that ideas which offend physical laws must be publicly demolished if they are not to be perpetuated, and that those which offend only existing geophysical data should at least be noted in a book of this kind so that they may be reconsidered if the balance of the evidence is changed as further research is carried out.

The new edition has enhanced the value of the book as a review of the subject and as a source of further information. It is to be hoped that Dr. Scheidegger is already collecting material for the third edition that will surely be necessary within the next few years.