But there are other ways of demonstrating this lower cold current. At a meeting of the Geographical Society Dr. Carpenter exhibited in a simple and minute way these warm and cold currents. He had a trough constructed with plate glass sides, about six feet long, a foot deep, and the sides not more than one inch from each other. At one end of this trough a piece of ice was wedged in between the two sides. That represented the Polar area. At the other end heat was applied by a bar of metal laid on the upper surface of the water, and the end carried over the trough and heated with a spirit lamp—to represent the equatorial area. Then some coloring matter was put in the water; red at the warm end, and blue at the cold end. Now what took place? The water tinged with blue, put in at the surface of the Polar area, being subject to a cold atmospheric temperature immediately fell to the bottom. It then crept slowly along the bottom of the trough, and at the warm end it gradually rose toward the surface, and gradually returned along the surface to the point from which it started. The red followed the same course as the blue, but started from a different point. It crept along the surface from the Equatorial to the Polar end, and there fell to the bottom, just as the blue had done, and formed another stratum, creeping along the bottom and coming again to the surface. Each color made a distinct circulation during the half hour that the experiment was under observation. Now this is an experiment that can be repeated in our parlors without going down to the Equator or up to the North pole; an additional proof that we often have the very thing at our doors that we travel thousands of miles to find. Until the last four or five years the opinion prevailed that the ocean was barren of life at great depths. Continued researches, however, find that many forms and great profusion of life exists at a depth of two and three miles. This deep water life seems to be adapted to the low temperature near the freezing point of fresh water—and the forms are usually very small, requiring thousands to weigh a grain. There is an exuberance of that small animal known as _globagerina_—the little animal that secretes carbonate of lime for a covering, and makes pretty much all our chalk beds. The well known “White Cliffs of England” were made by this little animal, and in the deeper portions of the Atlantic it is still at work. Some day when the ocean’s bed is raised a few thousand feet these beds of chalk will appear and be exactly like the chalk of the _cretaceous period_, so much talked of and written about by geologists. Again, there are other animals dredged lately in larger quantities at a great depth, 3,000 and 4,000 feet, belonging to the sponges. These are busy in making _flints_—or such material as flints are composed of.