It is a remarkable fact that when a room is well heated, and a door is opened leading into a cold room, that there will be two opposite currents of air producedthe warm will form the upper and the cold the lower one. To this we may have an occulnr demonstration by holding a lighted candle at the top of the door, upon which we shall discover that the flame is drawn along with the warm current into the cold room ; and by holding the candle at the bottom of the door, the flame will be drawn along with the cold current into the warm room. But what seems to be, indeed, the most remarkable of all, is, that the same cause seems to produce the sameeffectupon the vast oceans of our globe. Almost every school-boy has heard about that wonderful stream, some distance from our eastern shores, called the Gulf Stream ; similar streams are tound in nearly all parts f eaeh ocean in the world, being tormed at the equator, and flowing north in the northern hemisphere, or south in the southern hemisphere, the water being always the warmest at the surface ; some of these streams have been traced as far north as latitude 67", near Icy Cape. The warm equatorial streams are flowing towards the north and the cold polar streams towards the equator, the cold ones immediately under the warm ones, in an opposite direction ; and hence the body of cold water lying at depths, in the regions of the equator, which cannot be accounted for in any other way than by submarine currents from the polar seas. I close by giving the following extract from one of our most celebrated navigators : " We may see the admirable provisions of nature, by which the Creator has regulated the fluid mass ot the ocean, in its endless gyrations, seeking to attain a state of equilibrium, which it never reaches, at the same time and by the same cause distributing the excess of tropical heat throughout the whole surface of the globe, and bringing to the equator the icy masses, which would otherwise accumulate in the frozen zones." ABRAHAM RUDISILL. Carlisle, Pa, Dec. 14, 1852.