dark subterranean passages, would, in fact, be sufficient to throw the whole into confusion; but such an accident rarely happens, although works of the kind are common in the Cornish mines.”[21] As an illustration of the immense quantity of water in the mines, we may add—and this is almost as startling as any romantic fiction—that the various branches of the principal level in Cornwall, called “the Great Adit, which receives the waters of the numerous mines in Gwennap, and near Redruth, measure on the whole about 26,000 fathoms, or nearly thirty miles in length; one branch only, at Cardrew mine, extends for nearly five miles and a half, and penetrates ground seventy fathoms beneath the surface. The water flows into a valley communicating with a small inlet of the sea, and is discharged about forty feet above high-water mark.”[22] In this method about forty millions of tons of water are raised by steam-power out of the mines in Cornwall. [Illustration: EAST WHEAL CROFLY COPPER MINE, CORNWALL. ] Here, then, we have seen two of the economic uses of geology in connexion with _granite_ alone; and as we think of these mineral treasures, requiring only the labour and skill of man to bring them out for his service and for the civilization of the world, our boast is in our native land, which, though insular and small, combines within itself everything needful to develop its three sources of national wealth—mining, manufactures, and agriculture—to their highest point. Our boast is not the warrior’s boast, which Shakspeare puts into the mouth of one of his heroes—that this our isle is “That pale, that white-faced shore, Whose foot spurns back the ocean’s roaring tides, And coops from other lands her islanders”— but rather that, without impropriety or irreverence, the words of Holy Writ may as legitimately be applied to Great Britain as to Palestine. It is a land wherein “thou shalt eat bread without scarceness, thou shalt not lack anything in it; a land whose stones are iron, and out of whose hills thou mayest dig brass.[23] When thou hast eaten and art full, then thou shalt bless the Lord thy God for the good land which He hath given thee.” (Deut. viii. 9, 10.)