44 REWARDS TO THE SLAVES. "Poor negroes!" said James: "that is slaving for others, without hope for themselves!" "Not quite so," said his father. "It sometimes happens that a negro finds a diamond of larger size than usual; one that weighs seventeen and a half carats; and this is a happy day for him. He is directly crowned with a wreath of flowers, and led in gay procession to the proper magistrate, who immediately pays his owner the price of his liberty, and sets him free. He also receives a present of new clothes, and may work on his own account, if he pleases. Smaller diamonds may gain rewards, if they exceed certain fixed sizes. If a negro is suspected to have swallowed one, he is kept in close confinement till the fact can be ascertained. "When these treasures were first discovered in Brazil, diamonds were obtained in great plenty. The first fleet from that country brought so large SUBSTANCE OF THE DIAMOND. 45 a number, that orders were sent over from the Portuguese government to decrease the number of hands employed in searching for them; lest their abundance should make them quite common things, and, by lowering the price of those already brought over, spoil the trade. "It is very remarkable, that diamonds are of the same substance as charcoal; a fact which, in the progress of your studies, you will be made acquainted with. To many persons it must appear incredible that the darkest and the brightest substances in nature should be so nearly allied. "What are called Bristol and Cornish diamonds, are only crystallized quartz, and bear more relation to the Amethyst, the Garnet, and the Cornelian, than to the true diamond. They are, however, very hard, and sometimes possess considerable brilliancy, though real diamonds are very far superior to them in both these qualities." TIN. CORNWALL. "WE have come over a rather dreary country," said James. "I do not much like those barren moors of Cornwall. What a continual up and down it was! There seemed to be no end to the hills; and they were all so wild, rugged, and bleak!" "Every county in England has its specific character. Many smiling vales there are, rich in pasture and in grain; and many woody hills, with their dense darkness or thin light foliage waving beneath the blue sky, in the most picturesque manner; but, in general, it is not among such scenery that we should expect to find minest underground. We are come in quest of sub terraneous treasures; and these bleak unsightly moors promise well for our gratification." JAMES." And how strong the wind was, papa! Yet I saw in some of the valleys beautiful myrtles in full blossom; such as we can hardly rear in our greenhouses." "We are now near St. Austle: the Tin-Mines at Polgooth are our immediate object, about two miles distant." Section of a Tin-mine. Explanation of the section of a thick vein of "What a number of mines is here!" said James; "if one may judge from the steamengines." "Yes. There are between twenty and thirty now in use. The descent into them is by a perpen dicular pit called a shaft; and above fifty Shaft for opening Mineral Veins, and mode of working with windlass; bucket and miner at the bottom. shafts may be counted: though they are not all worked at the present day." "What are those tall buildings for ?" "Those are the engine-houses. Water is always very trou blesome in these |