156 SCIENCE PROGRESS 



The major portion of the memoir consists of detailed regional studies, the 

 whole of Australia being divided into fifteen regions whose physiography is 

 discussed with the aid of numerous maps and diagrams. In these studies such 

 matters as topography, drainage, vegetation, rainfall distribution, health, economics, 

 etc., are dealt with. 



The memoir forms an important contribution to our knowledge of the meteor- 

 ology of Australia. Meteorology often consists merely in the endless compilation 

 of statistics of one sort and another, which are put to little or no use. The studies 

 of Australian climate, upon which Mr. Griffith Taylor is engaged, ensure that this 

 will not be the case in Australia. 



H. S. J. 



A Star Atlas and Telescopic Handbook. By A. S. Norton, B.A. [Pp. 26, 

 with 16 maps.] (London : Gall and Inglis, 1919. Price 8s. 6d. net.) 



The appearance of a second edition of Norton's useful little star atlas is 

 worthy of mention. The atlas contains 16 maps, opening in pairs. Successive 

 sheets have a wide overlap, so that on one folio about one-fifth of the entire 

 heavens is seen at once. Some 6,500 stars and 600 nebula? are shown for the 

 epoch 1920, so that practically all the naked-eye stars are included. The new 

 edition will form an excellent companion to the new edition of Webb's Celestial 

 Objects for Common Telescopes. The opportunity has been taken to correct 

 errors in the first edition : the introductory matter has been extended ; amongst 

 the material added being an index to the sketch-map of the moon, notes on lunar 

 formations, etc. The atlas will prove of great use to students and amateurs. 



H. S. J. 



PHYSICS 



Mirrors, Prisms and Lenses. A Text-book of Geometrical Optics. By 



James P. C. Southall. [Pp. xix + 579, with 247 diagrams.] (New 

 York: The Macmillan Company, 1918. Price iys. net.) 



In the preface to this volume the author remarks that "At present, geometrical 

 optics would seem to be a kind of Cinderella in the curriculum of physics, regarded, 

 perhaps, with a certain friendly toleration as a mathematical discipline not without 

 value, but hardly permitted to take rank on equal terms with her sister branches 

 of physics." Although this remark was intended to apply to American colleges 

 and universities, it was equally true, at least until quite recently, of this country. 

 The war roused us to a realisation of the importance of the study of geometrical 

 optics, and a department of Applied Optics was formed at the Imperial College of 

 Science and Technology, with immediate success. The superiority of the optical 

 designs of the German munitions of war over those of the British and French is 

 attributable largely to the importance which the Germans have attached to this 

 subject. 



The appearance of a comparatively elementary text-book by such an authority 

 as Prof. Southall is therefore very opportune. To a certain extent the volume is 

 an abridgment of his well-known treatise on The Principles and Methods of 

 Geometrical Optics, with, however, the addition of a considerable mass of new 

 matter, such as an account of the fundamental principles of ophthalmic lenses and 

 prisms. This latter is to be welcomed ; spectacle optics is now leaving behind 

 empirical methods and becoming a scientific subject, and its inclusion in a 

 scientific text-book will extend the appeal of the book to a wider circle of readers. 



