In 1930 Kerner-Marilaun’s book Paläoklimatologie was published in Berlin; since then no other critical discussion of the recent progress made in the study of past climates has been published in German. Schwarzbach has attempted to fill this gap, and well he has done it. As the book is based entirely on published matter it contains nothing new for a reviewer to report; it therefore only remains to describe the contents and the method of presentation.

As the author says in his preface, the book has much more the nature of a text-book or a hand-book than its predecessors such as Kerner-Marilaun’s book mentioned above or C. E. P. Brooks’ Climate through the Ages. It is therefore hardly the book for a beginner; but for anyone fairly well up in the earlier work it is a pleasure to read; for Schwarzbach has all the skill in marshalling his facts which has given German scientific hand-books so great a reputation.

Starting with two short chapters on the history of palaeoclimatology and the climate of the present time, the author gets down to a long and valuable summary of the methods used by palaeoclimatologists and of the kind of evidence, chiefly geological, which has to be used. This clears the way for the main part of the work—the story of the changes of climate in the history of the earth.

His method of presentation is convenient: a section is devoted to each of the main geological formations; each section commences with a short account of the geology of the formation, which is followed by a discussion of the evidence for the climatic factors, temperature, humidity (rainfall and aridity), wind, etc.; and is then brought to a close with a survey (Gesamtbild) occupying only a few lines, seldom more than ten. The sections are so short that it is possible to read the longest in a sitting, so that one has the details in mind when one comes to the survey, which is what one usually wishes to remember.

The book closes with a chapter on the theories which have been put forward in such profusion on the causes of the changes in climate; this occupies only 31 out of 192 pages. The author gives in the preface the following explanation of this meagre allowance: “the chapter on the cause of the climate changes is relatively short because, interesting as this subject is, to-day we still build on quaking ground—the collection of observations and facts is the pressing need of palaeoclimatology,” and heads the chapter with a quotation from Goethe: “Sei ruhig—es war nur gedacht.”