356 Scientific Intelligence. 



on the one hand, and of dogmatic textbook statements on the 

 other. The extended experience of Sir John Murray, naturalist 

 of the "Challenger" Expedition (1872-76), and of the "Michael 

 Sars " Expedition (1910), commands interest in any publication 

 which comes from his pen. While the book under review reveals 

 the author's well-known scientific demand for accuracy and 

 includes recent data and results of investigations, it is delightful 

 reading for those who are laymen in oceanographic research. 

 The scope of the book is indicated by the following chapter head- 

 ings: Historical notes; methods and instruments of deep-sea 

 research; the depth of the ocean; the waters of the ocean: 

 salinity, gases; the waters of the ocean, temperatm*e; the waters 

 of the ocean: compressibility, pressure, color, viscosity, penetra- 

 tion of light, tides, waves, seiches; oceanic circulation; life in the 

 ocean: plants; life in the ocean: animals; marine deposits; the 

 geospheres. The oceanographic maps (Pis. II- VI and XI) of 

 deeps, salinity, surface temperature, currents, density and deposits, 

 and plates of deep sea organisms, constitute a valuable feature of 

 the work. h. e. g. 



10. Descriptions of Land : A Text-book for Survey Students ; 

 by R. W. Cautley. Pp. ix, 89. New York, 1913 (The Mac- 

 millan Company). — A land surveyor or geologist working in 

 Canada will find Mr. Cautley's text of direct value, it is a com- 

 mon sense guide to a higher standard of accuracy in the descrip- 

 tion of public land. h. e. g. 



11. Interpretation of Anomalies of Gravity, by Grove Karl 

 Gilbert. Part C of Professional Paper 85, U. S. Geological 

 Survey, pp. 29-37, 1913. — Hayford and Bowie in their work on 

 gravity anomalies assumed in their computations that isostatic 

 compensation was uniform and distributed everywhere to a 

 uniform depth. Furthermore, that every topographic feature 

 was compensated for by a corresponding variation in density. 

 Having computed the value of gravity for each station on these 

 assumptions, the differences between the observed and computed 

 value gave the gravity anomaly. This they interpret as measur- 

 ing the degree of imperfection of isostatic adjustment. Gilbert 

 shows, however, that isostatic compensation could be perfect at 

 the bottom of a zone of compensation and yet moderate vertical 

 heterogeneities of density could give rise to anomalies as great 

 as those actually observed. Thus the mere existence of anomalies 

 does not prove departure from equilibrium. Variation in the 

 depth of compensation could also give rise to anomalies. Still 

 further, variations in density below the zone of compensation, 

 the results of nucleal heterogeneity, would also give anomalies at 

 the surface. Thus the latter cannot be used as measures of 

 departures from isostatic adjustment until all these other factors 

 are evaluated. Gilbert has thus opened up a new aspect of the 

 discussion of the problem of equilibrium in the earth's crust. 



J. B. 



12. The Mud Lumps at the Mouths of the Mississippi, by 

 Eugene Wesley Shaw. Pp. 10-27 ; figs. 6, pis. iii, 1913. Part B of 



