Nature seems to have just the right adjustment in all its affairs, whether in coloring of flowers, season for growth, flavoring of fruits, supplies for animal and vegetable life, and instincts for everything created, to adapt them to living purposes. So in the Earth’s diurnal revolution of 24 hours, supposing it was slowed to 25 hours, we should have less wind and tides, less warmth and more land free from the encroachment of the sea. Increase the speed to 23 hours would give us more warmth by greater friction, increase the flow of our springs, give higher tides, and make most of the present commercial seaports of the world take seats farther back, as millions of acres of land now available would be flooded every tide. The moon, we are told, has little or no atmosphere. It is pronounced cold and uninhabitable. This all looks reasonable. Being only a little over 2,000 miles in diameter and a revolution about like the Earth through a thin atmosphere, it is easy to see the lack of friction to produce warmth, and therewith the proper constituents to sustain life. This is an easy one and readily disposed of. VI. EARTHQUAKES. It is doubtful if the Earth’s crust exceeds, or equals 1,000 miles in thickness. The outside is held from flying to pieces by the atmosphere, which is a sort of tire to the earth, while the inside is constantly pressing from effect of centrifugal force. These two factors must meet somewhere. On the outside, near the ice belt, the water pressure gets the best of the inner forces and drives the waters into Symmes’s Hole. In the Earth the centrifugal force has advantage until reaching the surface; but if a big hole could be cut at the Equator through to the center, no doubt a man could jump into it in safety and cease to fall as he cushioned against centrifugal influence in his descent. Earthquakes are only the effects of internal pressure of water to get to the surface, at times bursting large reservoirs, producing tremblings, and at others with great force throwing up hills and mountains from the tops of which the fountains of water burst forth. At other times they are produced by the contact of water with heated elements in volcanoes, creating the commotion leading to the volcanic eruption, the latter of which can only be produced by contact of fire and water. It is believed that this is the complete and brief explanation of earthquake causes. VII. VOLCANOES. The volcano is nothing more than a local fire, as much in connection with the Earth’s surface as the furnace fire built in a man’s basement to warm his house, or in his stove to cook his breakfast. When the fuel that is used in either one is consumed, the fire goes out, which is a common result in both cases. Of all the volcanoes known to have existed as evidenced by their craters, fully three-fourths have become extinct.