=332. Introduction of new industries.=—Machinery has not only revolutionized old industries; it has created many new ones. A distinguished American economist expressed the opinion, about 1890, that half of all those who were then earning their living by industrial pursuits did so in occupations that not only had no existence, but which had not even been conceived of, a hundred years before. I may write with a steel pen, with a fountain pen, or with a typewriter; whichever choice I make I am giving employment to a group of mechanical laborers who did not exist in 1800. Taking a particular city as an example, the industrial specialities of Leipzig are said to have increased from 118 in 1751 to 557 in 1890, a growth of 372 per cent. Nor must we limit our view of the effects of machinery to the mechanical pursuits which are carried on about us. Increased efficiency due to the use of machinery has set men free from other pursuits to engage in commerce, education, domestic service, etc. =333. Importance of iron in the age of machinery.=—One particular industry deserves special consideration here, by reason of the quality of its product rather than of the quantity of laborers employed or the mere exchange value of the output. Without iron the modern age of machinery would be, at best, of stunted growth. Jevons characterized admirably the modern industrial system when he said that steam is its motive power and iron is the fulcrum and the lever. It is safe, I think, to challenge the ordinary reader of the present day to name a machine which is not composed largely or almost wholly of iron. The whole structure of our modern industry depends on the means of getting cheap iron. “Without it the engine, the spinning-jenny, the power-loom, the gas- and water-pipe, the iron vessel, the bridge, the railway—in fact, each one of our most important works—would be impracticable from the want and cost of material.” =334. Scarcity of iron before the nineteenth century.=—Returning to the period about 1800 we find ourselves in a different world. I have described in a previous chapter the improvements effected in the manufacture of iron in the eighteenth century. Great as was the promise of these improvements, it waited long for full realization; well into the nineteenth century iron remained relatively scarce and dear and was spared in every possible way. A youth destined to play a leading part in the iron age (Joseph Nasmyth) visited the Carron Iron Works in 1823, and here is the description which he gives of a celebrated foundry and machine shop, associated with the construction of the first working steam-engine by Watt. “Much of the machinery continued to be of wood. Although effective in a general way it was monstrously cumbrous. It gave the idea of vast power and capability of resistance, while it was far from being so in reality.” If this was the condition at the Carron Iron Works, what must it have been in ordinary factories?