Page:A hundred years hence - the expectations of an optimist (IA hundredyearshenc00russrich).pdf/118



a forecast like the present it is impossible to avoid a certain amount of overlapping in different sections of the subject and a certain blending of topics in a single chapter. The attempt to differentiate consistently between the progress of science as science, and the concurrent advance of practical invention by which scientific discovery is turned to use would only involve needless repetition. I have already had occasion to suggest elements of material progress which presuppose the advance in pure science that would make them possible. Thus, in endeavouring to suggest what the methods of commerce and the condition of our cities are likely to be in the future it was necessary to conceive certain advances in our knowledge of what is rather clumsily called "wireless" telegraphy, and to predict the discovery of new and cheap methods of analysing water into its component gases as a source of fuel and as means for the production of electricity: and in order