Having considered the earth with the bodies that are therein, let us now look up to those that surround it. The world is a congeries of innumberable bodies, many of which are supposed to exceed the size of the earth: yet by reason of their distance, most of them are invisible to ‘the naked eye.

The nearest to us is the moon, which moves round the earth in less than twenty-eight days from west to east. The sun likewise seems to move from east to west, and shines successively on all parts of the globe. It appears also to us to move every year obliquely from west to east, coming twenty-three degrees and a half to the north, and then globe just as far to the south.

2. Some of the stars keep always the same distance with respect to each other and are termed fixed. Others are continually changing their situation, whence they are termed planets. Two of these, Mercury ‘and’ Venus, are frequently between the earth and the sun; of which the former being generally hid by the rays of the sun, is seldom-visible: but Venus, commonly called the evening star, is very conspicuous. The earth is never between them and the sun. They are sometimes between us and him. Sometimes the sun is interposed between us and them.

3. The upper planets are Mars, Jupiter, and Saturn. The sun is sometimes between these and the earth. But none of them is ever interposed between the earth and the sun. Mars has different appearances, like the moon, as it is differently situated, with regard to the sun whereas Jupiter and Saturn always appear with the same aspect, and have smaller planets revolving round them. All these revolve round the sun, in their several stated periods.

4. Beside these, there are another kind of stars, called comets, vulgarly, blazing stars. These do not revolve round the sun in so regular orbits as the planets. The fixed stars are above these: These have a vivid light, and always appear with the same face towards us: they seem to have a twofold motion, a slow one from east to west in as year, and a swift one round the earth with all the other stars in and twenty hours. But there are some of them which never set, namely those near the north or south pole.

5. To explain these phenomena of the heavenly bodies, various systems have been invented. The Ptolemaic supposes the earth to be fixed, in the centre of the universe, round which all the heavenly bodies move, each affixed to a solid sphere which moves with it: first the moon, then Mercury, thirdly, Venus, next the sun, filthy, Mars, then Jupiter, seventhly, Saturn. In the eighth place is the firmament or sphere of fixed stars: then the crystaline heaven, and last of all the primum mobile, which is supposed to move from east to west in twenty-four hours, whirling all the other spheres with it. But this system being in some respects obviously false, in others utterly improbable, and likewise: insufficient to account for many phenomena, is now universally exploded.

6. In the room of this, the Copernican system is now generally received, which supposes the sun to be fixed in the centre, without. any other motion, than that round his own axis. Next him is Mercury, then Venus, thirdly the Earth, (round which the moon revolves,) above the earth, Mars, then Jupiter and Saturn, with their attendant moons.

This system is extremely simple and natural, and easily accounts for most phenomena. As to the objection, that it is contrary to the testimony of our senses, it is easily answered. They who are in a ship seem to see the shore and the land moving along, although it is really the ship that moves. Yet let it move ever so swiftly, it displaces nothing, provided it moves smoothly So neither does the motion of the earth displace any thing on its surface, because it is equable and regular.

Not that Copernicus was the inventor of this system. It was in great part known long ago. Pythagoras taught, “ that the earth was carried about the sun among the stars, and by turning round its axis, caused day and night.” Yet by degrees it sunk into oblivion, till it was revived by cardinal Cusa. However, the Ptolemaic system still prevailed, till Nicholas Copernicus, a canon of Thorn, in Polish Prussia. born in the year 1473, had resolution to examine it thoroughly, and learning enough to explain and defend it. Some of the reasons on which this system is founded are, 1. This is most simple and agreeable to the whole tenure of nature: for by the motions of the earth all the phenomena of the heavens are resolved, which on any of the other hypothesis are utterly inexplicable. 2. It is more rational to suppose the earth moves round the sun, than that the huge bodies of the planets and of the sun itself, and the immense firmament of stars, should all move round the inconsiderable body of earth every four and twenty hours. 3. The earth’s moving round the sun is agreeable to that general harmony and universal law, which all other moving bodies of the system observe, namely, that the squares of the periodical times are as the cubes of the distances. But if the sun move round the earth, that law is destroyed, and the general order and symmetry of nature interrupted; because, according to that law, the sun would be so far from revolving about the earth in 365 days, that it would require not less than 5106 years, to finish one revolution. 4. The sun is the fountain of light and heat, which it darts through the whole system, and therefore it ought to be placed, as the heart in the that so all the planets may at all times have them, in an uniform and equal manner. 5. If the sun be placed in the centre of the system we have then the rational hypothesis of the planets being all moved about the sun, by the universal law of gravity: and everything will answer to that law ; but otherwise we are wholly in the dark. 6. But we need not rely upon conjectures. We have demonstrable proofs, that the sun possesses the centre, and that the planets , move-round it, in the order above mentioned. For example: Mercury and Venus are ever observed to have two conjunctions with the sun but no opposition, which could not happen unless the orbits of those planets lay within the orbit of the earth. And in the same manner it may be demonstrated, that the orbits of Mars, Jupiter and Saturn lie without the orbit of the earth.

7.After Copernicus came Tyco Brahe, a noble Dane, who endeavoured to compound a system, of the Ptolemaic and Copernican put together; but it was quickly found by all unprejudiced judges, to be “So intricate and perplexed, that it had not many assertors even while he lived, and is now well nigh sunk into oblivion,

8. Numerous hypothesis have been formed to explain the relative situation and character of our globe, and the motions and appearances of the heavenly bodies, the greater number of which have been evidently absurd and erroneous. Some have been marked by greater degrees of ingenuity, and plausibility, than others, which have nevertheless been rejected, as science progressed to more extensive degree of developement. Besides the Ptolemaic, and the Tychonic systems, other systems were projected which had many advocates. The Semitychonic, supposed the planets to revolve round the sun, while the sun and moon revolve round the earth, as their centre of motion, but this system supposed the diurnal motion of the globe, on its own axis. In this, it differs from the Tychonic.

The Cartesian system was next introduced. This proposed a variety of vortices, or whirlpools, in the etherial regions, in which the motions of the heavenly bodies were performed, in different times, proportioned to their distances; and each planet having a particular vortex of its own, in which the motions of its satellites were performed. But this appeared equally destitute. of analogy, and fact, for support. Besides it was evident, that the irregularities in motions of the planets, could not be accounted for on this hypothesis.

The Ptolemaic system bad gained universal credit when Copernicus began to entertain doubts of its truth ; and to try if a more rational scheme could not be projected, to account for the motions of the heavenly bodies. He had recourse to every means, for information, and found from Cicero, that Nichetas, a Syracusian astronomer, had maintained the doctrine of the rotatory motion of the earth. And that Pythagoras and others of the ancients had maintained the same opinion.

From these small hints, this great genius deduced a most complete system of astronomy, capable of solving every phenomenon in a satisfactory manner, a system which has been amply confirmed by the discoveries and improvements in astronomy, since that time. Like alt important discoveries however, when they run counter to popular prejudices, this system was very much opposed, and Copernicus him self considered as a wild theorist.

But while philosophers were divided between the Ptolemaic, the Tychonic, the Cartesian. and the Copernican systems, Sir Isaac Newton stepped forward in the plenitude of genius, and like a mighty umpire, laid down the laws of nature and of motion, and by comparing all the phenomena of the heavens, found out the true system of the universe, and confirmed the Copernican system. He demonstrated by unanswerable arguments, that it could not possibly be otherwise, without the utter subversion of all the laws of nature.

It would be endless to recount all the conjectures which have been made, respecting the constituent parts of the universe. Mr. Hutchinson supposed the following divisions. 1. The darkness, or dark air, or the fine ether, in the state of stagnation. 2. The spirit, or the air in sensible motion. 3. The light, or the pure ether in motion. 4. The luminaries, comprehending the sun, moon, and stars. 5. The densities, which form the extremity of the whole system of nature: or the dense gross air, out of which the fine ether is extracted, and into which it returns. He considered that the regions of space would be naturally grosser and grosser, the farther from the sun, and that the utmost extremity would be condensed into an immoveable solid. But since the discoveries and observations of Dr. Herschell on the nebulosity of the heavens, (which we shall take a brief survey of, when treating of the fixed stars,) very different conjectures and theories have been substituted. It now appears a more probable and rational conjecture, that our solar system is but one of innumerable systems; that the universe is of infinite extension, and occupied by an infinite multitude of worlds; that the sovereignty of the Creator is not limited to a comparatively insignificant and solitary world, or system, but that it is infinite as his wisdom, and extensive as his power. By the application, and great improvement of telescopic powers, the ideas of the universe has been much enlarged-; assisted and corroborated by handmaids of philosophy, science, and analogy. And we derive new views and prospects of the constituent parts of nature, and of universe, from recent experiments, and the great improvements, and discoveries in chemical philosophy. Hence we contemplate the universe as a boundless expanse, interspersed with contiguous systems; and worlds, suspended at distances proportionate to their mutual powers of attraction, and capable or reciprocating causes and effects hence we contemplate the nebulous patches of the heavens, as so many systems, and the galaxy as a zone of systems; and hence also we contemplate the sun as the centre of its particular system, comprehending the worlds which revolve round it as their common centre.

It was formerly imagined that the sun was a globe of liquid fire, from an idea that heat travelled to us from the sun: and the conclusion was naturally deduced, that the nearer the sun, the greater the heat. But this is found to be evidently erroneous. Notwithstanding Sir Isaac Newton calculated the heat of a comet at its nearest approach to the sun, to be 2000 times hotter than red hot iron; it was evidently en the assumption, that the sun was a globe of fire, and that the intensity of the beat, was in a ratio, proportionate to the distances. But this does not correspond with experience, for it is decisively ascertained, that the most intense cold prevails, at small elevations, in a direct line between us and the sun, even in the hottest parts of the globe under the equinox; towards the summits of very high mountains, where the cold has been found so intense, that it was with difficulty, life could be supported. The like has also been experienced, in the ascent in balloons, when the aeronauts have attatned to a great height, they have experienced intense cold, even when the weather has been intensely warm, on the surface of the earth. It is further evident that heat and fire, are mere local effects, from the various changes of the atmosphere, and from the phenomenon of hail in summer, when the drops of rain coming in contact with a cold region of air, are divested of their caloric, and instead of descending in a shower of water, descend in a shower of ice’. Hence it is sufficiently apparent that the elementary matter of heat, and fire, does not travel to very great distances in the atmosphere, but that it is confined to narrow limits near the surface of the earth, that it is a subtile elementary body, which can be alternately collected, and dissipated, in a great variety .f degrees by a great variety of circumstances. And these various effects, exactly correspond with the modern discoveries, experiments and doctrines of that subtile elementary substance, caloric.

These ideas would naturally introduce the mind, to a more connected, systematic. and rational train of reflection, on the sublime and interesting subjects of astronomy, and the philosophy connected with it. They would exhibit nature on a more extended scale of grandeur and simplicity. They would tend to harmonize the universe, and unfold the true relations of nature. They would display in more enlarged characters, and appropriate features, the universal creation, and the universal Creator. They would show that immortality was stamped on the universe; that the essential principle of all being, and of every species of being, was active, immutable, and universal. It would tend to excite in the mind of the creature reverence, gratitude and piety. And give an importance to being, even the meanest of the works of God.

Thus much premised, we shall proceed to survey the various phenomena of the heavens.