204 FIELDS, FACTORIES AND WORKSHOPS. 



than half a century elapsed before the theory reappeared 

 in science. Lamarck, and even Linnaeus, Geoffroy Saint- 

 Hilaire, Erasmus Darwin, and several others were fully 

 aware of the variability of species ; they were opening 

 the way for the construction of biology on the principles 

 of variation ; but here, again, half a century was wasted 

 before the variability of species was brought again 

 to the front ; and we all remember how Darwin's ideas 

 were carried on and forced on the attention of university 

 people, chiefly by persons who were not professional 

 scientists themselves ; and yet in Darwin's hands the 

 theory of evolution surely was narrowed, owing to the 

 overwhelming importance given to only one factor of 

 evolution. For many years past astronomy has been 

 needing a careful revision of the Kant and Laplace's 

 hypothesis ; but no theory is yet forthcoming which 

 would compel general acceptance. Geology surely has 

 made wonderful progress in the reconstitution of the 

 palaeontological record, but dynamical geology progresses 

 at a despairingly slow rate ; while all future progress in 

 the great question as to the laws of distribution of living 

 organisms on the surface oi the earth is hampered by 

 the want of knowledge as to the extension of glaciation 

 during the Quaternary epoch.* In short, in each branch 



* The rate of progress in the recently so popular Glacial Period ques- 

 tion was strikingly slow. Already Venetz in 1821 and Esmarck in 1823 

 had explained the erratic phenomena by the glaciation of Europe. 

 Agassiz came forth with the glaciation of the Alps, the Jura mountains, 

 and Scotland, about 1840 ; and five years later, Guyot had published his 

 maps of the routes followed by Alpine boulders. But forty-two years 

 elapsed after Venetz wrote before one geologist of mark (Lyell) dared 

 timidly to accept his theory, even to a limited extent the most interesting 

 fact being that Guyot's maps, considered as irrelevant in 1845, were 

 recognised as conclusive after 1863. Even now half a century after 

 Agassiz's first work Agassiz's views are not yet either refuted or 

 generally accepted. So also Forbes's views upon the plasticity of ice. 

 Let me add, by the way, that the whole polemics as to the viscosity of 

 ice is a striking instance of how facts, scientific terms, and experimental 

 methods quite familiar to building engineers, were ignored by those who 

 took part in the polemics. If these facts, terms and methods were taken 

 into account, the polemics would not have raged for years with no result. 

 Like instances, to show how science suffers from a want of acquaintance 



