Similar changes followed in cotton-spinning and other industries, and the result was to alter the whole economic structure of England. The cottager could not afford the new and expensive machinery, and his spinning-wheels and hand-looms were hopelessly beaten in the competition. Huge factories were required for the new inventions, where the workers were all huddled together instead of working in their scattered homes; and large populations grew up around these new and artificial manufacturing centres. Their locality was, however, determined by natural causes; at first water-power was the best available force to drive the new machines, and consequently towns sprang up along the banks of rivers. But Watt's application of steam- power to machinery soon supplanted water; and for steam-power coal and iron were the greatest necessities. Factories therefore tended to congregate where coal and iron were found; and the need for these materials created the coal and iron industries. Moreover, the pack- horse, the waggon, and the old unmetalled roads soon proved inadequate for the new requirements of transport. For a time canals became the favourite substitute, and many were constructed. Then Macadam invented his method of making roads; finally, Stephenson developed the steam locomotive, and the railway system came into existence. Closely connected with these changes was a renewal of the inclosure movement. The introduction of turnips and other roots, and the development of the rotation of crops increased the value of the soil and revived the stimulus to inclosure; and hundreds of inclosure acts were hurriedly passed by a parliament which contained no representatives of those who suffered from the process. It was assisted by the further specialization consequent upon the industrial revolution; while the agricultural labourer gave up spinning under the stress of factory competition, the spinner deserted his cottage and four acres in the country, to seek a dwelling near the factory which employed him; and the Elizabethan Act, insisting upon the allocation of four acres to each new cottage built, was repealed. But for that repeal, factory slums would be garden cities, unless the incubus of this provision had stopped the factory development. The final result of the inclosure movement upon the country was to deprive the public of most of its commons and open spaces, to deprive the agricultural labourer of all right in the soil he tilled, and to rob him of that magic of property which, in Arthur Young's phrase, turned sand into gold.