277. It is found in every country, that the situation of large manufacturing establishments is confined to particular districts. In the earlier history of a manufacturing community, before cheap modes of transport have been extensively introduced, it will almost always be found that manufactories are placed near those spots in which nature has produced the raw material: especially in the case of articles of great weight, and in those the value of which depends more upon the material than upon the labour expended on it. Most of the metallic ores being exceedingly heavy, and being mixed up with large quantities of weighty and useless materials, must be smelted at no great distance from the spot which affords them: fuel and power are the requisites for reducing them; and any considerable fall of water in the vicinity will naturally be resorted to for aid in the coarser exertions of physical force; for pounding the ore, for blowing the furnaces, or for hammering and rolling out the iron. There are indeed peculiar circumstances which will modify this. Iron, coal, and limestone, commonly occur in the same tracts; but the union of the fuel in the same locality with the ore does not exist with respect to other metals. The tracts generally the most productive of metallic ores are, geologically speaking, different from those affording coal: thus in Cornwall there are veins of copper and of tin, but no beds of coal. The copper ore, which requires a very large quantity of fuel for its reduction, is sent by sea to the coalfields of Wales, and is smelted at Swansea; whilst the vessels which convey it, take back coals to work the steam-engines for draining the mines, and to smelt the tin, which requires for that purpose a much smaller quantity of fuel than copper.