The machinery that is now employed in the iron trade, not only enables the people to be supplied cheaply with all sorts of articles of iron, but it enables a great number of people to find employment, not in the iron trade only, but in all other trades, who otherwise could not have been employed; and it enables everybody to do more work with the same exertion by giving them better tools; while it makes all more comfortable by furnishing them with more commodious domestic utensils. There are thousands of families on the face of the earth, that would be glad to exchange all they have for a tin kettle, or an iron pot, which can be bought anywhere in the three kingdoms for a shilling or two. And could the poor man in this country but once see how even the rich man in some other places must toil day after day before he can scrape or grind a stone so as to be able to boil a little water in it, or make it serve for a lamp, he would account himself a poor man no more. An English gipsy carries about with him more of the conveniences of life than are enjoyed by the chiefs or rulers in countries which naturally have much finer climates than that of England. But they have no machinery, and therefore they are wretched. Great Britain is a country rich in other minerals than iron-stone and coal. Our earliest ancestors are recorded to have exchanged tin with maritime people who came to our shores. They had lead also, which was cast into oblong blocks during the Roman occupation of the island, and which bear the imperial stamp. At the beginning of the eighteenth century we worked tin into pewter, which, in the shape of plates, had superseded wooden trenchers. But we raised and smelted no copper, importing it unwrought. The valuable tin and copper mines of Cornwall were imperfectly worked in the middle of the last century, because the water which overflowed them was only removed by hydraulic engines, the best of which was introduced in 1700. When Watt had reconstructed the steam-engine, steam-power began to be employed in draining the Cornwall mines. In 1780, 24,443 tons of copper-ore were raised, producing 2932 tons of copper. In 1850, 155,025 tons of ore were obtained, producing 12,254 tons of copper. The tin-mines produced 1600 tons in 1750, and 10,719 tons in 1849. The produce of the lead-mines has not been accurately estimated. [Illustration: Entrance to the Mine of Odin, an ancient Lead-mine in Derbyshire.]