The Mediterranean Sea, a body of water between Europe and Africa, nearly 2,000 miles in length, surrounded with most of the noted cities of antiquity, has remained during these thousands of years in an unchanged condition from tides, inundations, or any other disturbing causes. Into this sea through the Strait of Gibraltar has been flowing all this time from the Atlantic Ocean, a river 15 miles wide with an average depth of one and one-fourth miles. This river is reported to have so strong a current that a sailing vessel has difficulty of coming out against it without the help of a favorable east wind. This is a sufficient flow of water to fill the basin of the sea almost yearly, besides the help of all the rivers of Southern Europe and Northern Africa. The reason of no change is given for its location, where evaporation carries off all this influx of water; while some think an undercurrent must exist back into the Atlantic. The first reason seems too ridiculous for a child to give. The water of the Atlantic is so salt as to produce over a pound of salt to a common bucket full. If evaporation is the reason of its equable condition, there could be no other result than a mountain of salt big as the Himalayas long before this time. The claim of a countercurrent is almost as absurd. That the sea discharges its waters in an undercurrent which passes through the neighborhood of the Caspian and Aral Seas, is more likely than that the waters run backward against a powerful current from the Atlantic and against the centrifugal force that governs the movements of relatively every other water course on the Earth. So much for that subject for any criticisms that may be offered. Intervening lakes between the Caspian and Aral Seas, seasonably fill with salt water, from the evaporation of which immense bodies of salt are gathered. Where does this supply of salt water come from to leave hundreds of thousands of tons of salt each year? XVIII. SURFACE INFLUENCES OF WATER, AND CHANGE OF POLARITY. Very little thought or attention is paid to the insidious changes produced by water on the Earth’s surface. Not a day passes, or has gone by, but that a large quantity of material is transferred from one locality to another. Every shower carries from some higher point to a lower, and a certain amount of drift goes toward some ocean. Small streams contribute to the larger ones, and all lead to the great ocean reservoirs. In going across our country many important evidences are to be seen of the immensity of work accomplished by water, in the removal of vast areas and depths of land.