September 23, 1915] 



NATURE 



99 



Carbons ; Theory of the Submarine Telegraph Cable, 

 Dr. H. W. Malcolm; Wireless Telegraphy and Tele- 

 phony, Dr. W. H. Eccles; Electric Switch and Con- 

 trolling Gear, Dr. C. C. Garrard; The Electrical 

 Laboratory and Testing Room, vols, i, and ii.. Dr. 

 J. A. Fleming; Primary Batteries: their Construction 

 and Use, W. R. Cooper, new edition ; The 

 Localisation of Faults in Electric Light Mains, 

 F. C. Raphael, new edition. C. Griffin and 

 Co., Ltd. — Refractory Materials : their Manu- 

 facture and Uses, A. B. Searle, illustrated ; 

 Vinegar : its Manufacture and Examination, C. A. 

 Mitchell, illustrated ; The Construction of Dams 

 (Rarthen and Masonry), Prof. E. R. Matthews, illus- 

 trated; Briquetting : Coal, Shale, Ores, Metal Swarf, 

 <tc., G. Franke, translated and edited by F. Lants- 

 berrv', 2 vols. ; Autogenous Welding, R. Granjon and 

 P. Rosemberg, translated by D. Richardson, new 

 edition. H. Holt and Co. (New York). — Commerce 

 and Industry, J. R. Smith. John Wiley and Sons, 

 Inc. (New York).- — Decorative Design : A Text-Book 

 (if Practical Method, J. C. Chase; Mechanical Draft- 

 ing, C. B. Howe. 



Miscellaneous. 

 George Allen and Unwin, Ltd. — The Great 

 Problems, Prof. B. Varisco, translated by Prof. R. C. 

 Lodge; Know Thyself, Prof. B. Varisco, translated 

 hv Dr. G. Salvadori. Duckworth and Co. — Founda- 

 lions of Normal and Abnormal Psvchologv, Dr. B. 

 Sidis; Child Training, C. V. Hi'llyer, illustrated. 

 Wells Gardner, Dalton and Co., Ltd. — Story Lives of 

 Men of Science, F. J. Rowbotham. C. Grijjin and 

 ( o., Ltd. — Practical Surveying and Field- Work, in- 

 cluding the Mechanical Forms of Office Calculations, 

 with Examples, completely worked out, V. G. Salmon ; 

 Practical Hydraulics for Mining Students, Prof. J. Park, 

 illustrated; Theodolite Surveying, Prof. J. Park, new 

 edition, illustrated; .\n Enquiry into the Statistics of 

 Deaths from Violence and Unnatural Causes in the 

 United Kingdom : with Special Reference to Deaths 

 from Starvation, Overlying of Infants, Burning, Ad- 

 ministration of Anaesthetics, and Poisoning, Dr. W. A. 

 Brend. Longmans and Co. — What Should I Believe? 

 An Inquiry into the Nature, Grounds and Value of 

 Science, Society, Morals, and Religion, Prof. G. T. 

 Ladd. Macynillan and Co., Ltd. — Second Thoughts 

 of an Economist, the late Prof. W. Smart; An Intro- 

 duction to Ethics for Training Colleges, G. A. John- 

 ston ; Mind in Evolution, L. T. Hobhouse, ne\y edition. 

 Methuen and Co.. Ltd. — Government by Natural 

 Selection, H. Taylor. G. P. Putnam's Sons. — Social 

 Progress and the Darwinian Theory, Dr. G. W. Nas- 

 inyth; Darwin and the Humanities, Dr. J. M. Bald- 

 win. John Wiley and Sons, Inc. (New York). — A 

 Meteorological Treatise on the Circulation and Radia- 

 tion in the Atmospheres of the Earth and of the Sun, 

 Prof. F. H. Bigelow. 



THE BRITISH ASSOCIATION. 

 SECTION C. 



GEOLOGY. 



Opening Address * by Prof. Grenville A. J. Cole, 

 F.G.S., M.R.I. A., President of the Section. 

 The geologist has long been accustomed to regard 

 the crust beneath his feet as subject to chanees 

 which are immeasurably slow in comparison 

 with the duration of his personal life. James 

 Ilutton has sometimes been charged with catas- 

 trophic tendencies, in requiring a complete wear- 

 ing away of the continents, followed by a somewhat 



1 Abridged by the author. 



NO. 2395, VOL. 96] 



sudden restoration of the land-surface. But he was 

 careful to urge - that " the powers of nature are not to 

 be employed in order to destroy the very object of 

 those powers ; we are not to make nature act in viola- 

 tion to that order which we actually observe." He r^r 

 marks ^ that " this world is thus destroyed in one part, 

 but it is renewed in another; and the operations by 

 which this world is thus constantly renewed are as 

 evident to the scientific eye as are those in which it is 

 necessarily destroyed." Yet the operations that are to 

 " give birth to future continents," as well as those that 

 wear down a continent to the level of the sea, are not 

 the result of " any violent exertion of power, such as 

 is required in order to produce a great event in little 

 time ; in nature, we find no deficiency in respect of 

 time, nor any limitation with regard to power." Far 

 from believing in the complete loss of the former 

 land-surface before upheaval raised the new, Hutton 

 points out that "the just view is this, that when the 

 former land of the globe had been complete, so as to 

 begin to waste and be impaired by the encroachment 

 of the sea, the present land began to appear above 

 the surface of the ocean. In this manner we suppose 

 a due proportion to be always preserved of land and 

 water upon the surface of the globe, for the purpose 

 of a habitable world, such as this which we possess." 



Changes in the Relative Proportions of Sea and Land. 



Few geologists, however, will now urge with 

 Hutton that a "due proportion" has always been pre- 

 served between land and water on the surface of the 

 globe, if by those words is meant a proportion such 

 as we now enjoy. If we go back to early times, we 

 must consider, with R. A. Daly,* the possible group- 

 ing of the land against which the Huronian or late 

 pre-Cambrian sediments were formed. Daly has 

 imagined, as one of the causes contributing to a 

 "limeless ocean," a primitive distribution of land and 

 water very different from that which determines our 

 continental land to-day. His pre-Huronian land- 

 surface is pictured as merely a number of large islands, 

 on which no long and conspicuous rivers could arise. 



It may be said that this primitive condition of the 

 distribution of land and water is very unlikely to 

 return. But we have evidence that Hutton's "due 

 proportion" has been interfered with from time to time. 

 The very general spread of the sea over the land- 

 margins in Cenomanian times is attributable to a 

 shallowing of the ocean-floors, and it is difficult to 

 say whether this process has been rhythmic or excep- 

 tional in the history of the globe. The Carboniferous 

 period opened with marine conditions over a large 

 part of the northern hemisphere, indicating, not only 

 a continuation of the Devonian seas, but an overflow- 

 ing of much of the Caledonian land. The same period 

 closes with an extension of the continental edges, and 

 the formation of swampy flats, in which the vegeta- 

 tion of the epoch has been abundantly preserved. 

 Similarly, the sea which deposited the Cretaceous 

 strata, after encroaching alike on South Africa and 

 Scandinavia, withdrew to a considerable extent in 

 Eocene times. 



The Foundations of the Earth's Crust. 

 Hutton remains at present unassailable in one 

 of his most remarkable propositions. For him, 

 the oldest rocks that we know are sedimentary, and 

 these sediments differed in no respect from those of 

 modern days. This conclusion has perhaps not re- 

 ceived the full attention it deserves. It now appears 



2 "Theory of the Earth " (1795), vol. ii., p. 547. 



S //;/■</., p. 562. 



* "The Limeless Ocean of Pre-CamSrian Time," Amer. Journ. Sci., 

 vol. xxiii. (1007), p. 113 ; and more fully in ' First Calcareous Fossils," 

 Bull. Ceol. Sac. America, vol. xx. (1909), p. 157. 



