Ages before the dawn of civilization, primitive man had learned to extract certain ores and metals from the earth by subterranean mining. Such nations as the Egyptians, for example, understood mining in most of its phases, and worked their mines in practically the same manner as all succeeding nations before the time of the introduction of the steam engine. The early Britons were good miners and the products of their mines were carried to the Orient by the Phoenicians many centuries before the Christian era. The Romans were, of course, great miners, and remains of the Roman mines are still in existence, particularly good examples being found in Spain. Even the aborigines of North America possessed some knowledge of mining, as attested by the ancient copper mines in the Lake Superior region, although by the time of the discovery of America, and probably many centuries before, the interloping races of Indians who had driven out or exterminated the Lake Superior copper mines had forgotten the art of mining, if indeed they had ever learned it. But the fact that their predecessors had worked the copper mines is shown by the number of stone mining implements found in the ancient excavations about Lake Superior, these implements being found literally by cart loads in some places. The great progress in mining methods, however, as in the case of most other mechanical arts, began with the introduction of steam as a means of utilizing energy; and another revolution is in rapid progress owing to the perfection of electrical apparatus for furnishing power, heat, and light. Methods of mining a hundred years ago were undoubtedly somewhat in advance of the methods used by the ancients; but the gap was not a wide one, and the progress made by decades after the introduction of steam has been infinitely greater than the progress made by centuries previous to that time. This progress, of course, applies to all kinds of mines and all phases of mining; but steam and electricity are not alone responsible for the great nineteenth-century progress. Geology, an unknown science a century ago, has played a most active and important part; and chemistry, whose birth as a science dates from the opening years of the nineteenth century, is responsible for many of the great advances.