to be a satellite to the earth, so long as the Sun and Moon and earth thus exist. Whether all satellites are in a similar condition it would be impossible to decide; the distance of their nearest to us (Jupiter's) being too great to enable us to pronounce anything certain. Though it has been said by Mr. Proctor, and others, that they do not appear to be in the same condition as regards their rotation, and, unlike our Moon, show symptoms of a more rapid and complete rotation on their axis,* proved by their varying light and change of spots on their surface, and appearing sometimes as black spots, at transits across Jupiter's disc, and at other times. as bright ones; from which Mr. Proctor argues, that they are unlike our Moon, and are probably seats of life and intelligence, while their primary, Jupiter, is a minor sun from which they derive their light. This may be the case, but at such a vast distance as they are situated it would not be easy to determine anything certain respecting their condition. Nor amidst the infinite and wonderful variety conspicuous in the heavens as in all nature, and the continual changes occurring there, would it be safe (viewing them analogically from our own Moon) to classify all satellites as in the same condition. In whatever way, however, we regard the Moon, whether in reference to her beauty or utility, we must be blind. not to see the benevolent design which has given her to us as a satellite, whose soft and mild lustre rules and cheers the night, and whose power governs every wave

The revolution and rotation of the Moon on her axis nearly coincide; the effect of which is to cause her to present invariably the same face to the earth.

that breaks upon our shores; and whose coming, appearance, and temporary departure from us, marks familiarly and pleasantly the division of the weeks and months and years of our own lives' history. These, at all events, may justly be considered practically as "the precious things put forth by the Moon," which we have every reason for believing will continue "so long as the Sun and the Moon herself endureth."

CHAPTER VI.

ASSOCIATION OF COMETS AND STAR SHOWERS.

"And behold a great red dragon. . . . and his tail drew the third part of the stars of heaven."-REV. xii. 3.

OMETS may truly be considered as the enigma of the heavens. Suns and planets have yielded their many wonders, in some degree, to the insatiable curiosity and intelligence of the little restless being who, stationed on his grain of sand called earth, has surveyed and scrutinized them for thousands of years. Misty nebulæ, and flying meteors, and distant firmaments have surrendered at discretion and laid open their wonders and real nature, and laid down their arms before the eye and intelligence of man armed with his telescopic tube or spectroscopic weapon; all have more or less been conquered, but comets-these flaming swords of heaven, these mysterious startling apparitions, -still defy research, and, though they spread themselves ostentatiously across the whole hemisphere as though to invite deliberate attention and investigation, they still continue to evade scrutiny, now aweing the ignorant or superstitious, now challenging and puzzling the scientific world. Though every motion has been observed and ascertained, their orbits calculated, their inner movements watched by thousands of curious eyes

and telescopes, all as yet is in vain. There shines the mysterious head with its dull vaporous light and brilliant nucleus within; there spreads the wondrous tail, now fanned, now forked, now multiplied into many tails, and spread over millions and millions of miles of the heavens. But what is actually known about comets? What is their nature and what their purpose and use in creation? To what class of bodies can they be referred?

No reply that can be depended on has as yet been given to any of these questions, and comets are still one of the mysteries of creation which remains yet to be unfolded. Many ingenious solutions of it have been suggested of more or less weight; but after all they are but guess work, and most of them as improbable as they are unproved.

Yet, in these days, at least within the last five years, it has been thought a recent light has been thrown upon their nature, which may possibly lead to the resolution of at least a portion of the mystery in which they are enveloped. The recent discovery of the remarkable and exact coincidence of the orbits of two comets,-that of 1862, called Tempel's, and 1866, with the orbits of the two principal systems of meteors, forming the splendid meteoric showers of August and November, 1866,—has led astronomers to the natural conclusion of the association of these systems in some way with comets, but in what way has not yet been proved. There are many other meteoric systems that have been associated with known comets; but those of the August and November meteors are the only periods that have been actually determined to be identical with the orbits of the two comets in question. This discovery, first noted by

Schiaparelli, seemed at first to give some possible clue to the nature of these strange bodies, and when ascertained startled the scientific world of astronomers not a little.

An association of some kind of these great systems with the comets could no longer be doubted, and expectation was consequently raised that we had at last got the key to the mystery of the being of these strange visitants, and a shower of meteors was in fact but the encounter of the earth with some portion of the comet, or something attached to it and inseparable from itpossibly a portion of its tail constituting the innumerable meteorites that flashed upon us in 1866, and into the midst of which the earth plunged, and through which she passed on that memorable night. If so, comets would be but the condensed material of which the meteors are composed, leaving their tail or wake of star showers or cometary matter behind them as they rushed on their orbit.

Thus we seemed to be on the eve of a great discovery, and for aught I know we may be still; but as yet, at least, it has not advanced a single step further, and no such conclusion has been adopted positively or universally by the astronomical world of science-nor can it be proved; and though a most remarkable association between the star showers in question and the two comets referred to has been shown and acknowledged, the actual nature of the association has not been ascertained, and the mystery of the physical condition of these bodies and their use in the universe is as great as ever; indeed, remarkable as the association is, there is nothing in the appearance of a comet to warrant its