Rensselaer Republican, Volume 12, Number 15, Rensselaer, Jasper County, 26 December 1879 — The Moon and Earth. [ARTICLE]

The Moon and Earth.

Then if we pass back into the preceding ages we must compute the time for the earth to cool down from a molten state. Bischoff, the German, determines by experiments with molten rock, and he is supported by Helmholtz, that the period required for the earth to cool from 2,000 deg. Centri§rade to 200 deg. is 350,000,000 years. ischoff probably erred in underestimating rather than in overestimating tho period; but if we take this period as probable and add to it the succeeding time, we have 450,000,000 years since the earth was a nebular mass, and in round numbers may declare 500,000,000 years the age of our planet. Much longer periods are required for the larger planets. In estimating time in planetary life wo must apply Newton’s principle that the larger the planet the longer the stages of its., existence. We find that if we heat two iron balls, one an inch in diameter and the other two inches in diameter, it will take twice as long for the latter to cool as the former, for although it has four times as much mass it has eight times as much surface from which all heat must depart. The planet Jupiter in mass is nearly 843 times as large as the earth* 843 is equal to the cube of seven; for Jupiter, then, to reach the same density of the earth, it would -take seven times as many years, or seven times 350,000,000, equal to 2,450,000,000, and allowing the same proportion for subsequent changes, for Jupiter to reach the point the earth has would require 3,500,000,000, or 3,000,000,000 more years than the earth. But Jupiter is still far younger in development than is our planet. When we turn to the sun we reach far higher figures. Following the same rule, as the mass of the sun is 340,000 times greater than that of the earth, its age will be seventy times a 3 great, and we find that it would take 35,000,000,000 years for the sun to reach the earth’s present state. Considering the smaller orbs, as the moon, we find that the past period is comparatively brief; but that the earth will reach the same condition far in the remote future. The moon in mass is 81 times less than the'earth, and its surface is as 1 to 13. By dividing 81 by 13 we find how many times the comparative age of the moon is less than the earth’s. This gives 83,000,000 years as the time it took for the moon to reach a condition similar to the pres-' ent stage of the earth’s existence. The earth is behind the moon about 420,000,000 years, and, as the moon goes on six times as fast as the earth, 420,000,000 multiplied by 6 gives us 2,500,000,000 years before we shall see the earth as the moon now is. From the present condition of the moon we learn what to expect on our ear tip Our planet, now in full life, will in 2,500,000,000 years be in extreme old age. These periods of enormous duration of time sink into insignificance before the history of the solar system as a whole. We find a wide relation between the parts of the solar system, in that all the planets, from the mightiest globe to the smallest satellite, except one of Uranus, move in their paths in the same direction. Astronomers would be as muA surprised to see one of the asteroids — of which 200 have been discovered—going in the opposite direction as to see the sun rise in the west.

All the heavenly bodies are pails of some mighty whole. By the nebular hypothesis, the whole solar system was once an enormous mass of gaseous matter, which began turning like a disc. Then the outer part became dissevered and formed one orb; the next and the next followed, until there was only a central sun left to rule the entire systefli. Each planet went through the same process, rings after rings and satellites after satellites were formed. This nebular theory accounts for the general features. It is not opposed by facts. The meteoric system must also be considered. Professor Newton, of Y ale College, estimates that the earth is increased by 400,000,000 every vear. This may amount to t housands of tons of matter, but it is nothing as compared with the mass of the earth. Still we may say the earth is growing; but her growth is only like that of one who has already attained full stature. These meteors are only the residue of a residue, the few left out of the millions of the past. In the remote ages the earth must have met far more. From a rough calculation I made, I find that my assumption must have been wrong, or the earth would have increased ten-fold more than she did. But we may rightly contend that no small part of the mass of the earth is formed from meteoric aggregations. If we tak,e La Place’s theory with the meteoric, we may account. for the present condition of our planet. And as the earth, and indeed all matter we know—our bodies and brains—have come down from the heavens, is it any wonder that all our higher thoughts 'and aspirations are heavenward?— Rcj>ort in N. Y. Tribune of a licccnt Lecture by Prof. Proctor.

—Elucidation: Rector’s Wife—“ How do you do, Mr. Wiggles? We have not seen you at church lately. Have you been away?” Mr. Wiggles—“ Yes, mu'm; I’ve been a-visitin’ my old ’aunts at Manchester, niu’m.” Rector’s Wife— * ‘ Really! I hope you found the old ladies quite well.” Mr. Wiggles—“l didn’t say myhamts, mu’rn - l said my old ’aunts—revisitin’ the ’aunts o’ my youth, you know, mu’m!”