484 



NATURE 



[June 16, 192 1 



considerations are here applied to the analysis of 

 what occurs in the steam turbine as a whole. 



The book is completed by three appendices ; 

 the first is on general thermodynamic relations, 

 and the second is on the use of a steam diagram 

 in which the co-ordinates are the total heat and 

 the logarithm of the pressure. The third appendix 

 gives the steam tables in the same form as that 

 in which they were separately presented in his 

 earlier publication. 



It is not a book for beginners : it will be intel- 

 ligible only to those who have a working know- 

 ledge of general thermodynamics and are fairly 

 familiar with the use of partial differential co- 

 efficients. But engineers and physicists who have 

 this equipment will find it a valuable work of 

 reference. They will welcome so detailed a state- 

 ment of original views and methods from one 

 whom they gratefully recognise as a leader and a 

 pioneer. Prof. Callendar writes with the autho- 

 rity of an investigator whose knowledge of steam 

 and its properties is probably unique. 



J. A. EwiNG. 



Ore Deposits of Utah. 



The Ore Deposits of Utah. By B. S. Butler, 

 G. F. Loughlin, V. C. Heikes, and Others. 

 (U.S. Geol. Surv. Professional Paper iii.) 

 Pp. 672 + lvii plates. (Washington, D.C. : 

 Government Printing Office, 1920.) i^ dollars. 



THE series of monographs in preparation by 

 the Geological Survey of the United States to 

 summarise existing knowledge of the ore deposits 

 of the separate American States will render readily 

 available much valuable information now dis- 

 persed through a voluminous and scattered 

 literature. The first of the series was on New 

 Mexico (1910). The second deals with Utah, an 

 area of special interest as regards both its geo- 

 logical structure and the variety of its ore de- 

 posits. The study of Utah has introduced many 

 new conceptions into structural geology ; some 

 of them, like that of the laccolite, a term intro- 

 duced for the Henry Mountains by Gilbert, have 

 been fully confirmed ; others, such as the support 

 to antecedent rivers by the oft-quoted case of the 

 Green River, have been set aside by fuller know- 

 ledge of the facts, or, like the igneous sequences 

 proposed by Button and Spurr, are dismissed as 

 too uncertain. 



Utah has given exceptionally clear evidence of 

 the importance of block faulting in determining 

 the existing relief, and of the cause of such fault- 

 ing by subsidence after long periods of igneous 

 activity and earth movement. The views of le 

 Conte and Suess, based on the earlier studies of 

 NO. 2694, VOL. 107] 



Utah, are fully justified by the latest contributions 

 to its geology. The tectonic history of the region 

 presents a significant coincidence with that of 

 Africa in the importance of east-to-west folds in 

 the late Cretaceous, and of subsequent north-to- 

 south faults that may be even still in progress. 



The economic geology of Utah is especially 

 instructive on account of the remarkable variety 

 of its ore deposits. Some, such as the silver sand- 

 stones, are well known owing to the controversy 

 as to the origin of the ores ; the authors of this 

 survey adopt Lindgren's conclusion that they 

 were sedimentary grains concentrated by hot 

 water in consequence of the igneous intrusions. 

 Probably the most valuable general conclusion in 

 the volume (pp. 196-201, and the instructive dia- 

 gram, Fig. 31) is that the quantity of the ore 

 deposits beside masses of intrusive igneous rock 

 depends on the lowering of the surface by de- 

 nudation. This principle had been previously 

 used to explain the contrast between the gold 

 veins in the adjacent fields of Bendigo and Castle- 

 main in Victoria, and also the fact that the ores 

 beside the granites of Burma are richer beside 

 narrow than beside the wider outcrops. It re- 

 ceives its fullest and most authoritative expres- 

 sion in this volume. The clearness of the dia- 

 grammatic figures of the ore bodies and tectonic 

 structures is an especially notable feature of this 

 important and well-executed monograph. 



Medical Science and Practice. 



(i) Obstetrics : Normal and Operative. By Prof. 

 G. P. Shears. Third edition, revised by Dr. 

 P. F. Williams. Pp. xxii + 745. (Philadelphia 

 and London: J. B. Lippincott Co., 1920.) 

 35s. net. 



(2) Principles and Practice of Operative Dentistry, 

 By Dr. J. S. Marshall. Fifth edition. Pp. 

 xxix4-7ii -hxvi plates. (Philadelphia and 

 London: J. B. Lippincott Co., 1920.) 355. net. 



(3) Diagnosis and Treatment of Brain Injuries : 

 With and Without a Fracture of the Skull. By 

 Prof. W. Sharpe. Pp. vii + 757. (Philadelphia 

 and London: J. B. Lippincott Co., 1920.) 

 355. net. 



(4) Lippincott' s Quick Reference Book for Medi- 

 cine and Surgery. By Dr. G. E. Rehberger. 

 (Philadelphia and London : J. B. Lippincott 

 Co., 1920.) 635. net. 



MESSRS. LIPPINCOTT'S series of text- 

 books on medical subjects is well known in 

 this country. Many of the volumes, as is 

 the case with two of the four under review, have 

 already reached the third or later editions. 



Like ' nearly all American books, they are 



