394 SCIENCE PROGRESS 



GEOLOGY. By G. W. Tyrrell, A.R.C.Sc, F.G.S., University, Glasgow. 

 Structural and Dynamical Geology 



Oldham, R. D., The Structure of the Himalayas, and of the Gangetic Plain, as 

 Elucidated by Geodetic Observations in India, Mem. Geo/. Survey of India 

 1917,42, pt. 2, pp. 153. 



MacMillan, W. D., On the Hypothesis of Isostasy,/^™. Geo/. 1917, 25, 105-11. 

 Bowie, W., Our Present Knowledge of Isostasy from Geodetic Evidence, ibid. 

 422-45. 



Wood, H. O., Notes on the 1916 Eruption of Mauna Loa, ibid. 322-36, 467-88. 

 JAGGAR, T. A., Vulcanologic Investigations at Kilauea, Amer. Journ. Sci. 1917, 



44, 161-220. 

 Washington, H. S., Persistence of Vents at Stromboli and its Bearing on 



Volcanic Mechanism, Bui/. Geo/. Soc. Amer. 191 7, 28, 249-78. 



The examination of geodetic evidence in the Gangetic and 

 Himalayan region by Oldham shows that the general distribu- 

 tion of the excesses and defects of gravity agrees best with the 

 assumption of a somewhat rigid crust resting on a denser 

 yielding layer ; but that neither this, nor any other hypothesis 

 of support, has yielded a complete and satisfactory explanation 

 of the origin of the Himalayas, and of the deep alluvial trough 

 of the Gangetic plain. The theory of isostasy in relation to 

 geodetic evidence is further discussed by MacMillan and Bowie. 

 The papers of Wood and Jaggar contain perhaps the closest 

 observations of volcanic phenomena that have ever been made ; 

 and it is only by such constant and detailed study on the spot 

 that any real insight into volcanic mechanism will be obtained. 

 The " gas-fluxing " hypothesis of the origin of volcanic vents 

 enunciated by Daly has been applied by Washington to explain 

 the curious persistence in location of the six Stromboli vents 

 over a period of considerably more than a century. Their 

 unusual number, small size and contiguity over a restricted 

 area, their want of synchronism, and difference in type of 

 activity, are also best explained on Daly's hypothesis. 



Regional and Stratigraphical Geology 



Sinclair, J. H., The Cretaceous of Alberta, Bull. Geol. Soc. Amer. 1916, 27, 



673-84. 

 Martin, G. C, The Triassic Rocks of Alaska, ibid. 685-718. 

 Arber, E. A. N., The Structure of the South Staffordshire Coalfield, with Special 



Reference to the Concealed Areas and to the Neighbouring Fields, Trans. 



Inst. Min. Eng. 191 6, 52, pt. 1, 35-70. 

 Staplks, E. H., Some Effects of the Master Folds upon the Structure of the 



Bristol and Somerset Coalfields, ibid. 191 7, 52, pt. 2, 187-98. 



