The line of the greatest mean warmth is not coincident with the equator, but falls to the north of it. This line at 160° W. Long, from Greenwich is 4° below the geographical equator; at 80° it is about 6° north, sweeping along the coast of New Granada; at 20° it comes down and touches the equator; at 40° E. Long., it crosses the Red Sea about 16° north of the equator, and at 120° it falls at Borneo, several degrees below it;--and the points of the greatest heat, in this line, are in Abyssinia, nearer the tropic of Cancer than to the equator. On the other hand, the greatest mean cold points, according to the opinions of Humboldt, Sir David Brewster, and others, do not coincide, as would seem natural, with the geographical poles, but they are both to be found in the northern hemisphere, in Latitude 80°, 95°E. Long. and 100° W. Long. from Greenwich. The western is ascertained to be 4-1/2° colder than the eastern or Siberian. If this be the fact,--but it is not positively admitted,--an open sea at the pole may be considered as probable, on the ground of its having a higher mean temperature than is found at 80°. Kaemptz places one of these cold points at the north of Barrow's Straits,--the other near Cape Taimur, in Siberia. Burghaus, in his Atlas, transfers the American cold pole to 78° N. Lat. It is perhaps too early to determine rigorously the true temperature of these points. A noticeable fact also is this,--that places in the same latitude rarely receive the same amount of heat. Quebec, in British America, and Drontheim, in Norway, enjoy about the same quantity, while the former is in 47° and the latter in 68° N. Lat. The mean winter temperature of Pekin, 39° 45' N. Lat., is 5° below the freezing-point; while at Naples, which is north of Pekin, it seldom, if ever, goes below it, and Paris, 500 miles farther north, has a mean winter temperature of 6° above the freezing-point. The city of New York, about 11° south of London, has a winter temperature of much greater severity. The mean temperature of the State of New York, as determined by a long series of observations, is 44° 31'. The mean temperature of countries is found to be very stable, and but very small variations have been detected in modern times. But that there have been important climatic changes, since the Christian era, cannot be doubted, unless we doubt history. Not many centuries ago, it was a common thing for all the British rivers to freeze up during the winter, and to remain so for several months. If space permitted, an interesting statement could he made of the changes which have taken place in vegetation in Greenland, and throughout certain northern parts of Europe,--also in Palestine, Greece, and other southern countries,--while we know that the earth's inclination upon its axis has been unchanged.