In the middle of the last century there was comparatively little movement of workmen from place to place; but Adam Smith's fierce attack on the law of settlement shows that migration was on the increase. The world was, in fact, on the eve of an industrial revolution; and it is interesting to remember that the two men who did most to bring it about, Adam Smith and James Watt, met, as I have mentioned, in Glasgow, when one was dreaming of the book, and the other of the invention, which were to introduce a new industrial age.