Page:Gods Glory in the Heavens.djvu/216

188 a gaseous body. This is probably also the constitution of the zodiacal light, which is another ring or zone nearer the sun, the boundaries of which are not well defined. It is shaped somewhat like a quoit. The sun being in the middle of the central hole, we see only the edge of it when it appears to rise as a long cone from the horizon. It is best seen in February and March above the part of the horizon where the sun has set. The generally received opinion is, that it is composed of meteoric bodies; and some hold that it may extend beyond the orbit of the earth, so that we pass through it twice a year. The meteoric bodies become incandescent when they meet our atmosphere, and the two annual periods of meteoric showers are accounted for by the intersection of the earth's orbit at two opposite points. To an eye at a great distance, the sun would appear as if surrounded by two faint rings, with a wide, dark space between, while the outer ring, or that of the asteroids, would likely be subdivided by smaller dark lines.

The calculations of Leverrier, and the discovery of Lescarbault, render it very probable that there is a zone of planets or asteroids within the orbit of Mercury, so as to form a third faint ring encircling the sun. Leverrier has also shewn that the perturbation of Mars indicates the existence of a zone of meteorites whose diameter is nearly equal to that of the orbit of the earth. Such a zone Avould most naturally explain the phenomena of meteorites and their periodicity.