586 



SCIENCE 



[N. S. Vol. LII. No. 1355 



thousands of young lives were lost through its 

 neglect. When we bow our heads before the 

 .Cenotaph we think of the highly trained men 

 of science who were killed at Gallipoli or 

 drowned in the mud of Flanders while Minis- 

 ters turned for advice to alchemists and circle- 

 squarers, or confused great chemists with dis- 

 pensers of drugs, and we wonder whether even 

 now anyone in power realizes what civilization 

 has lost through the sacrifice of creators of 

 knowledge. "While we mourn their loss, let us 

 work and pray for the scientific enlightenment 

 of the leaders into whose hands the destinies of 

 the nation are entrusted, so that we may be 

 assured of strong and effective guidance what- 

 ever is before us. — Nature. 



SCIENTIFIC BOOKS 



The Geology of South Australia. By Walter 

 HowcHiN, Lecturer in Geology and Paleon- 

 tology in the University of Adelaide. Pub- 

 lished by the Education Department, Ade- 

 laide, 1918. Pp. xvi + 543. 

 Division I. of this book is a general review 

 of geologic processes and principles, with il- 

 lustrations drawn chiefly from the geology of 

 Australia. Incidentally, the illustrations bring 

 out many facts concerning Australian geology, 

 some of which are not readily available to the 

 general reader. For example, in the discus- 

 sion of deformation, it is stated that there are 

 two belts of " settlement " (subsidence), one 

 meridional, giving rise to the great rift valley, 

 the ends of which make the present great gulfs, 

 the other along the continental shelf at the 

 isouth, running northwest and southeast, its lo- 

 cation being about where the shallow sea floor 

 slopes down to the depths. Settlement still is 

 in progress in both these zones, and the earth- 

 quakes of Australia, of which two have been 

 recorded in recent times, one in 1897, and one 

 in 1902, are connected with the sinking. 



Division II. of the volume deals with the 

 historical geology of South Australia, but, for- 

 tunately, comprehensive notes are appended 

 concerning the geology of other parts of the 

 ^continent, so that this part of the book is a 

 summary of Australian geology, with chief em- 



phasis on South Australia. Brief correlation 

 notes tie up the geology of the continent with 

 that of England. The sections dealing with 

 the Cambrian and the Permo-Carboniferous 

 are perhaps of greatest interest because these 

 systems have large and instructive representa- 

 tion in the continent. The Cretaceous also is 

 represented in a large way. 



The volume has excellent illustrations, both 

 photographic and diagrammatic. The illus- 

 trations of Cambrian fossiliferous limestone, p. 

 377, are examples of the former, and the sec- 

 tion of Mt. Remarkable, p. 279, of the latter. 



The hope may be expressed that when a sec- 

 ond edition of the book shall appear, a little 

 more stress may be laid on the physical events 

 in the history of the continent, as for example, 

 the character, extent and dates of the principal 

 deformations. If knowledge permits their 

 preparation, paleographic maps would be most 

 welcome. The volume is a very useful one, 

 and adds much to our knowledge of the geol- 

 ogy of the continent. 



EoLLiN D. Sallisbury 



TJniversitt or Chicago 



SPECIAL ARTICLES 



THE COMPRESSION OF A SOUND WAVE 



Lord Eayleigh and more recently Professor 

 A. G. Webster and others have given consider- 

 able attention to this problem. The following 

 experiment, which is, I think, capable of exact 

 development, is a further contribution. 



1. Apparatus.— Manj years ago^ I showed 

 that displacement interferometry lent itself 

 favorably to the study of a diabatic expansion 

 and this is particularly the case when the 

 achromatic fringes are used. It is therefore 

 suggested that the endeavor to look with the 

 interferometer through the nodes of an organ 

 pipe would not be unsuccessful. 



Open pipes P, adapted for the purpose in 

 question, are shown in Figs 2, 3. In Fig. 2, 

 cylindrical adjutages pp'j of somewhat smaller 

 diameter than the pipe (open within, but 

 closed by glass plates gg on the outside) are 



1 Carnegie Pub. 149, Ch. XI., 1912. 



