[194] The rate of progress in the recently so popular Glacial Period question 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--more than 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 with facts and methods of experimenting both well known to engineers, florists, cattle-breeders, and so on, could be produced in numbers. [195] Chemistry is, to a great extent, an exception to the rule. Is it not because the chemist is to such an extent a manual worker? Besides, during the last ten years we see a decided revival in scientific inventiveness, especially in physics--that is, in a branch in which the engineer and the man of science meet so much together. [196] I leave on purpose these lines as they were in the first edition. All these desiderata are already accomplished facts. [197] The same remark ought to be made as regards the sociologists, and still more so the economists. What are most of them, including the socialists, doing, but studying chiefly the books previously written and the systems, instead of studying the _facts_ of the economical life of the nations, and the thousands of attempts at giving to agriculture and industry new forms of organisation and new methods, which are now made everywhere in Europe and America? CHAPTER IX. CONCLUSION.