Copper is of such common occurrence that it would be vain to enumerate the localities where it is found. It is produced in Africa and America, in Persia, India, China, and Japan. The Siberian mines are very productive both in ore and native copper. Malachite is the most beautiful of the ores, and the choicest specimens come from Siberia. Almost every country in Europe yields copper. The mines in Sweden, Norway, and Germany are very productive; and it forms a principal part of our own mineral wealth. It is raised in all the principal mining districts in England and Wales. In Cornwall it is very plentiful, and is often associated with tin. The period at which the Cornish mines were first worked goes far beyond history, or even tradition: certain, however, it is that the Phœnicians came to Britain for tin. Probably copper was also worked very early in small quantities, for its exportation was forbidden in the time of Henry VIII. It was only in the beginning of the eighteenth century that the Cornish copper-mines were worked with success, in consequence of the invention of an improved machine for draining them.[104] [On the lands south of Lake Superior is a body of copper ore, supposed to be the richest in the world. It is almost pure in some specimens: so that, as taken from the earth, it was wrought into church utensils by some of the French who first visited the place; and a portion of the large rock deposited on the grounds of the War Department, at Washington, has been polished so as to present the appearance of sheet-copper. At a recent meeting of the “American Association for the Advancement of Science,” held at Cambridge, Mass., August 1849, Mr. J. S. Hodge, speaking of the mineral region of Lake Superior, said:—“The mines are wrought wholly for native copper. The veinstone with scattered particles, furnish what is called _stamp work_; which is crushed under heavy stamps and then washed; the lumps are called _barrel ore_, being packed in barrels for transportation; and the masses, after being cut up into pieces not exceeding two tons in weight, are shipped in bulk. The size of some of these masses is so enormous as almost to exceed belief. They have been broken up in the Cliff mine of 60 and even 80 tons in weight. Such pieces are reduced, in the mine, to fragments of seven tons weight and less, and after being hoisted to the surface are still further reduced.