60 STUDIES, SCIENTIFIC AND SOCIAL chap. 



One after another, crude theories have been abandoned, 

 facts have steadily accumulated, and their logical though 

 cautious interpretation has led to a considerable body of 

 well-supported inductions on which the new science is 

 becoming firmly established. Some of the most important 

 and far-reaching of these inductions are, however, still 

 denied by writers who have a wide acquaintance with 

 modern glaciers ; and as several works have recently 

 appeared on both sides of the controversy, the time seems 

 appropriate for a popular sketch of the progress of the 

 glacial theory, together with a more detailed discussion of 

 some of the most disputed points as to which it seems to 

 the present writer that sound reasoning is even more 

 required than the further accumulation of facts.^ 



In the last century, Swedenborg, Linnaeus, Pallas, De 

 Luc, and many other eminent writers took notice of the 

 remarkable fact that in Scandinavia, Russia, Germany, 

 and Switzerland detached rocks or boulders were found, 

 often in great abundance and of immense size, and of a kind 

 that did not exist in situ in the same district, but which 

 were often only to be discovered in remote localities, some- 

 times hundreds of miles away. Those who ventured to 

 speculate on the origin of these travelled rocks usually 

 had recourse to water-power to account for their removal ; 

 and as their large size and often elevated position required 

 some unusual force to carry them, there arose the idea of 

 enormous floods sweeping over whole continents ; and for 

 a long time this diluvial theory was the only one that 

 appeared to be available, although the difficulties of its 

 application to explain all the phenomena became greater 

 the more closely those phenomena were studied. Still, 

 there was apparently no other known or conceivable means 

 of accounting for them, and for the enormous mounds of 



^ The works referred to are : — Do Glaciers Excavate? by Prof. T. G. 

 Bonney, F.R.S. {The Geographical Journal, vol. i., No. 6) ; The Glacial 

 Nightmare and the Flood, by Sir H. H. Howortli, M.P., F.R.S. ; 

 Fragments of Earth Lore, by Prof. James Geikie, F.R.S. ; Man and 

 the Glacial Period, by Prof. G. F. Wriglit, F.G.S.A. ; La Periode 

 Glaciaire, by A. Falsan ; and the Glacialists' Magazine, edited by Percy 

 F. Kendall, F.G.S. ; from which works, and from those of Lyell, 

 Ramsay, Geikie, and the American geologists, most of the fact 

 referred to in these chapters are derived. 



