The earliest life underground was in caves of natural formation. All over the globe there are caverns where men have lived, sometimes under concealment, sometimes for sanitary reasons, and sometimes because they saved the labor of constructing houses. Some of these caverns are of great dimensions, and could furnish shelter for thousands of men, while others are adapted to the wants of only a few persons. Many caverns and caves are not available as dwelling-places, but are visited only from motives of curiosity on the part of travellers, or from a desire for gain on the part of those who seek whatever may be valuable. Many caves have histories romantic or tragic, and some of them combine romance and tragedy in about equal proportions. Tales of love and war, of fidelity and treachery, and of all the contending passions and experiences of human nature, can be found in the histories of these excavations which have been made by no mortal hands. [Sidenote: MINING IN METAPHOR.] Metaphorically, there is a great deal of underground life above the surface of the earth. Men devote time, and patience, and study to the acquisition of wealth by measures that are as far removed from the light of honesty as the tunnel the miner drives beneath the mountain is removed from the light of the sun. One builds a reputation which another burrows beneath and destroys, as the engineers at Hell Gate undertook to destroy the rocky reef which sunk the ships of many a navigator, from the days of Hendrick Hudson to Gen. Newton. Hope springs eternal in the human breast, but it is not always hope for better things. Dishonest men hope for wealth, they care not how obtained, and in its pursuit they frequently imitate the labors of the miner. Shafts are sunk and tunnels are driven; the pick, the drill, and the powder-blast perform their work; operations are silently and secretly conducted, and all unknown to the outer world; dangers of falls of earth, of floods of water, of choke-damp, and fire-damp, are unheeded, and by and by the prize may be obtained. A great city, in its moral or immoral life, is cut and seamed with subterranean excavations more extensive than those of the richest coal-fields of England or Belgium. Wall Street is a mining centre greater than the whole of Pennsylvania, and to one who knows it intimately it reveals daily more shafts and tunnels than can be found in Nevada or Colorado. The career of a politician is not unlike that of the miner, though it is frequently much more difficult to follow. The miner may be tracked and found, but there is many a politician whose devious windings would baffle the keenest detective that ever lived. * * * * *