METEORS CONSIDERED.

New Zealand Tablet, Volume IV, Issue 191, 24 November 1876, Page 8

METEORS CONSIDERED.

The origin of meteors was long without receiving a satisfactory explanation, that most generally accepted being that they were caused by the existence of inflammatory gases in the atmosphere. The ignis fatuue, no doubt, is produced in this way, for it has been found to change its motion by the slight current of air preceeding a person walking toward it. But the intense velocity of the meteors that appear in August and November, which is about equal to twice that of the earth in its orbit, or thirty-six miles in a second, and the great elevation at which they become visible, the average being sixty miles, indicate clearly that they are not of terrestrial but cosmical origin — that is, they originate from the interplanetary regions, innumerable fragments of heavenly bodies that have been shattered to pieces traversing space, and, bein<* brought within the sphere of the earth's attraction, precipitate themselves upon its surface. Moving with the great velocity mentioned through the higher regions of the air they become so intensely heated by friction that they ignite, or are at least rendered visible, and are either converted into vapor, or, when very large, explode and descend to the earth's surface as meteoric stones or aerolites- Professor Thomson, of the British Association, says that they are "small bodies -which come into the earth's atmosphere, and the instant they touch it their surfaces are heated beyond the point of fusion or even of volatilization, and the consequence is that they are speedily and completely burned down and reduced to impalpable oxides." The brilliancy and color of meteors are variable; some are as bright as Venus or Jupiter. About two-thirds are white, the remainder yellow, orange or o-reen. The problem of their origin must be regarded as the same with that of the asteroids, revolving around the sun between the orbs of Mars and Jupiter, and of the planets themselves. Some astronomers consider their origin precisely the same as that of the comets, which may be regarded as only meteors oi vast size. The singular regularity and periodicity in the recurrence of the great manifestations of meteors in the months of August and November, which has been noted for many years, and with few exceptions their rushing from particular points of the heavens show still further that they are extraneous bodies encountered by the earth in the course of her revolution around the sun. In order to explain the occurrence of meteoric showers on the same days in August and November each year it is necessary to suppose that the number of these bodies is inconceivably great, and that they are revolving round the sun in orbits which intersect or meet our own

in the regions of the ecliptic through which we pass on those days. In addition, the fact, before stated, of their diverging from certain fixed points among the stars, and their great velocity strongly favor the idea of their foreign origin. The elements of their orbits correspond almost with the comets of 1862 and 1866 — the November meteors with the latter, and the August with the former, showing that the comets and these meteors belong to the same rings in which they move. It is probable that Biela's comet, in 1845, and others have been divided and sub-divide 1, so as finally to be separated into small fragments, moving in the orbit of the original comet, and thus constructing- a meteoric stream. — ' N. T. Herald.'