=Direction of Wind Affects Shore Temperature of Water.= Onshore winds skim off the warm surface water and drive it shoreward, where it banks up, and, pressing downward, causes the colder water beneath to flow back seaward. In like manner, offshore winds blow off the top water near the shore and send it out to sea, and colder water rises to take its place. =Great Heat of the Earth’s Interior.= We are ignorant of the conditions of matter under the heating effect of the enormous pressure that exists near the center of the earth, but it is probable that pressure prevents it from changing from a solid to a liquid or a gaseous form. The surface of the solid earth rises to a much higher temperature as the solar rays fall upon it than does a water surface, or the air immediately above, because it is a poor reflector, a poor conductor, and a poor radiator, and when dry does not get any cooling effect from evaporation. Solar heat ceases to be apparent at a depth that varies with the latitude and the conditions of the soil with regard to moisture and specific heat, but everywhere at less than fifty feet. At the poles and for some distance away the earth is covered with ice or snow the entire year and is frozen to a considerable depth. In the interior of Siberia and some parts of Alaska only a thin stratum of soil thaws out under the heat of summer. Beginning at about fifty feet, there is an increase of temperature downward, but it is not the same for all places, varying from a degree for forty feet to a degree for one hundred feet. Taking the average of the increase with depth, water would boil at ninety-five hundred feet and the hardest rock be molten at thirty miles. At a depth of 3490 feet near Berlin, the temperature was found to be 116°, while it was only 108° at the same depth at Wheeling, West Virginia, and in both places there is no change from day to night or from winter to summer. =Soil Usually Warmer Than Air Next Above.= In summer, June to August, the bare, dry, top soil is warmer than the air ten feet above during all hours of the day and night, at times the difference being as much as forty degrees at midday. During winter, December to February, it is slightly cooler, except between 9 A.M. and 3 P.M. when the excess is seldom more than ten degrees. Evaporation from a wet soil lowers its temperature below that of the air immediately above through the rendering latent of a large quantity of heat. A melting snow surface also is below the temperature of the air because of the heat employed in changing the snow to the liquid form.