Rensselaer Republican, Volume 18, Number 6, Rensselaer, Jasper County, 15 October 1885 — EARTH’S CHANGES. [ARTICLE]

EARTH’S CHANGES.

What Has Been and May Be Again. _ Prof. XL Ramus communicates to La Nouveille Revue an article on the earth and its changes, the glacial epoch and the final disappearance of ice from the planet, from which article the following is extracted: “During the whole period of the primary rocks and the formation of coal strata, tropical heat prevailed from latitude 35 degrees to 80 degrees—to the polar renions, that is. The temperature was uniform over the whole earth. During the first half of the second period, that of jurassic rocks and chalk, the Climate remained the same; the same plants ind the same animals were found all over the globe. During the second half of the period, however, the climate began to cool somewhat, and deciduous trees made their appearance, though tropical plants were still to be found in England and Denmark. Even to the ‘ middle of the tertiary period there Was an equality of climate in all latitudes; bur the temperature in Europe fell very gradually, and it is certain that at the end of the tertiary period there was no ice on the globe, not even at the poles or at the top of the highest mountains. “With the quaternary period a great change took place. The reindeer was to be found in all parts of Europe, the cold was excessive, and the great Swiss glaciers extended to the south of France. The glacial epoch was in full swing, and the uniformity of temperature formerly prevailing had been destroyed. Then a reflex action begins; the glaciers, and with them the reindeer and the mammoth, retreated as slowly as they advanced. At the furthest point of the glacial extension the cold became so intense that a sea of ice covered half Russia, all Prussia, Hanover, Holland and part of England. “What, then, was the cause of this change from uniformity to excessive cold over so large a portion of earth’s surface? And how is it that the extent of the cold region, after having reached its maximum, gradually retreated? We attribute the change to the deflection of the earth’s axis from the perpendicular and then its gradual return toward its old position. In the case of a perpendicular axis the climates will be nearly equable all over the globe; there will be some difference in different latitudes, owing to the fact that the sun’s rays are only vertical at the equator, but it will be comparatively small. There would be no nights long enough in any part of the planet to leave time for the formation of a large quantity of ice. Consequently all we have to do to account for the ages of time when the climate, as geology tells us, was the same all over the world, is to imagine the earth with a perpendicular axis in place of an ax s at an angle with the plane of the ecliptic as it is now. “The angle to-day is 23 degrees 27 minutes and 9 seconds. But the Chinese astronomer Choo Kung, who measured the angle 1,100 years before Christ, made it 23 degrees and 54 minutes. It will take the axis 176,946 years to move at its present rate through the distance which now separates it from the perpendicular. “As long as the axis remained perpendicular, the climate, as has been said, was uniformly hot, and in Greenland and Spitzbergen pomegranates grew. One day the axis began to change. At first this had a slight effect. For ages the modification was trifling; even at the tertiary period there was still no ice, and snow, when it fell, soon disappeared. But by degrees the zone was traced. Round the pole the change was already complete, and the radiation of the earth overcame the solar heat, and the night the day, so that masses of ice were fqrmed. The quaternary period was entered; man appeared on our continent; the angle of obliquity of the axis being about 15 degrees, and the polar belt, about 1,000 miles in extent, finished at the southern part of Spitzbergen. The glacial epoch had begun. "As to the age of man upon the earth, assuming that he did not appear until tne lower stages of the quaternary period, in which his bones are first found, it is certain that the climate was much warmer in Europe than it is now. On one calculation man has been 223,108 years on the earth, and 249,054 years have passed since the axis of the earth first moved out of the perpendicular. ”