The sun has two apparent motions, namely, the diurnal and annual. By the former he appears to move round the earth in twenty-four hours: and by the latter he appears to traverse that circle in the heavens, called the ecliptic, in the course of a year. These motions, are, however, only apparent: the sun does not travel round the earth in twenty four hours: he does not change his place in the heavens at different seasons of the year. His apparent motions are occasioned by the earth’s real motions. The sun’s apparent diurnal motion is occasioned by the earth’s real rotation about its axis: and the sun’s apparent annual motion is caused by the earth’s real motion in her orbit, through the whole of which she travels in a little less than 365 days, and 6 hours.

The fixed stars appear every twenty-four hours to make an entire revolution about the earth. The sun makes the same apparent circuit; but the apparent diurnal motion of the sun is evidently slower than that of the fixed stars. This appearance is occasioned by the daily rotation of the earth on its axis; for while it is turning once on its axis it advances in its orbit a whole degree; therefore it must make more than a complete rotation before it can come into the same position with the sun that it had the preceding day. In the same way, as when both hands of a watch set off together at any hour, as twelve o’clock, the minute hand must travel more than the whole circle before it can overtake the hour hand: hence the difference between solar and sidereal days, which it is important to understand in explaining the equation of time.

Though the sun appears to us merely as a circular disk, yet he is a spheroid, higher under his equator than about his poles. The deception arises from this; that all the parts of his surface are equally luminous, and consequently there is nothing which can suggest to us, at the great distance he is from the earth, that the central parts are more prominent than the sides, although in reality, they are nearer by half a million of miles.

This luminous body is supposed to be 886,473 English miles in diameter, about 2,700,000 in circumference, in solid bulk 24,000,000 times as big as the moon, and 1,384,462 times as big as the earth, and its superficies in square miles, about 2,236,603,000,000. This magnitude of the sun may appear exaggerated; for our eyes can discover nothing so large as the earth which we inhabit; and as to this alone we compare the sun, so we are tempted to believe the testimony of sense rather than our reason. But what confirms this prodigious size, is his visible magnitude, notwithstanding the vastly remote point which he occupies in space. And, concerning this subject, no doubt can remain, if we admit the calculations of astronomers, which are made on principles indubitably correct.

The sun does not appear large; but this is owing to his distance from the earth, which is 95,513,794 miles: this is so prodigious, that a cannon-ball, which is known to move at the rate of eight miles in a minute, would be something more than twenty-two years in going from the earth to the sun. If a spectator were placed as near to any of the fixed stars as we are to our sun, he would see our sun as small as we see a common star, divested of its circumvolving planets; and in numbering the stars he would reckon it one of them. But the earth’s orbit being an ellipse, the sun is not always at an equal distance from it. When he is in his apogee, that is, furthest from the earth, the sun is full two millions of miles further from us than when he is in his perigee, or nearest the earth: nevertheless, we feel greater heat than when he is in our winter. The difference of temperature between summer and winter does not depend chiefly upon our nearness to the sun, but upon the following causes. 1. In summer, the solar rays strike upon the earth more perpendicularly than in winter, and therefore they act with greater force than when they strike it obliquely. 2. The rays of the sun coming more perpendicularly in summer than in winter, have less of the atmosphere to pass through. 3. In the summer, the sun continues a longer time above the horizon than below it; and consequently there is time for the earth to accumulate a greater portion of heat than in the days of winter. We know, in the longest days, that the sun to us is above the horizon 16 hours; whereas, in the shortest days, it is not more than 8 hours visible.114

The miraculous suspension of the natural powers of the heavenly bodies, as recorded in the book of Joshua, shows that they are upheld, controlled, and directed in their operations, by a Being who is infinitely wise and powerful. To account for this miracle, and to ascertain the manner in which it was wrought, has employed the pens of the ablest divines and astronomers, especially of the last two centuries. For the elucidation of this important fact, I shall transcribe the view which Dr. Adam Clarke has given of it, which he considers to be strictly philosophical, consonant to the Pythagorean, Copernican, or Newtonian system, which is the system of the universe, laid down in the writings of Moses.

He assumes, as a thoroughly demonstrated truth, that the sun is in the centre of the system, moving only round his own axis, and the common centre of the gravity of the planetary system, while all the planets revolve round him; and that his influence is the cause of the diurnal and annual revolutions of the earth.

“Joshua’s address is in a poetic form in the original, and makes the two following hemistichs:

“The effect of this command is related in the following words: וידם השמש וירח עמד vayiddom ha-Shemesh ve-Yareach âmad; And the sun was dumb, or silent, and the moon stood still. And it is added, And the sun stood still in the midst of heaven, and hasted not to go down about a whole day.

“I consider, that the word דום dom, refers to the withholding or restraining this influence, so that the cessation of the earth’s motion might immediately take place. The desire of Joshua was, that the sun might not sink below the horizon; but as it appeared now to be over Gibeon, and the moon to be over the valley of Ajalon, he prayed that they might continue in these positions till the battle should be ended; or, in other words, that the day should be miraculously lengthened out.115

“Whether Joshua had a correct philosophical notion of the true system of the universe, is a subject that need not come into the present inquiry; but whether he spoke with strict propriety on this occasion, is a matter of importance, because he must be considered as acting under the Divine influence, in requesting the performance of such a stupendous miracle: and we may safely assert, that no man in his right mind would have thought of offering such a petition, had he not felt himself under some Divine afflatus. Leaving, therefore, his philosophical knowledge out of the question, he certainly spoke as if he had known that the solar influence was the cause of the earth’s rotation, and therefore, with the strictest philosophic propriety, he requested, that that influence might be for a time restrained, that the diurnal motion of the earth might be arrested, through which alone, the sun could be kept above the horizon, and the day be prolonged. His mode of expression evidently considers the sun as the great ruler or master in the system; and all the planets, (or at least the earth) moving in their respective orbits at his command. He therefore desires him, (in the name and by the authority of his Creator) to suspend his mandate with respect to the earth’s motion, and that of his satellite, the moon. Had he said, Earth, stand thou still—the cessation of whose diurnal motion was the effect of his command, it could not have obeyed him; as it is not even the secondary cause either of its annual motion round the sun, or its diurnal motion round its own axis. Instead of doing so, he speaks to the sun, the cause (under God) of all these motions, as his great archetype did, when, in the storm on the sea of Tiberias, he rebuked the wind first, and then said to the waves, Peace, be still! Σιωπα, πεφιμωσο, be silent! be dumb! And the effect of this command was, a cessation of the agitation in the sea, because the wind ceased to command it, that is, to exert its influence upon the waters.

“The terms in this command are worthy of particular note: Joshua does not say to the sun, Stand still, as if he had conceived him to be running his race round the earth; but, be silent, or inactive; that is, as I understand it, restrain thy influence; no longer act upon the earth, to cause it to revolve round its axis; a mode of speech which is certainly consistent with the strictest astronomical knowledge: and the writer of the account, whether Joshua himself, or the author of the Book of Jasher, in relating the consequence of this command, is equally accurate, using a word widely different, when he speaks of the effect, the retention of the solar influence had on the moon: in the first case, the sun was silent, or inactive, דום dom; in the latter, the moon stood still, עמד âmad. The standing still of the moon, or its continuance above the horizon, would be the natural effect of the cessation of the solar influence, which obliged the earth to discontinue her diurnal rotation, which, of course, would arrest the moon; and thus both it and the sun were kept above the horizon, probably for the space of a whole day. As to the address to the moon, it is not conceived in the same terms as that to the sun, and for the most obvious philosophical reason: all that is said is simply, and the moon on the vale of Ajalon, which may be thus understood: ‘Let the sun restrain his influence, or be inactive, as he appears now upon Gibeon, that the moon may continue as she appears now over the vale of Ajalon.’ It is worthy of remark, that every word in this poetic address is apparently selected with the greatest caution and precision.

“At the conclusion of the 13th verse, a different expression is used when it is said, So, the sun stood still, it is not דום dom, but עמד âmad; ויעמד השמש vai-yaâmod ha-shemesh, which expression, thus varying from that in the command of Joshua, may be considered as implying, that in order to restrain his influence, which I have assumed to be the cause of the earth’s motion, the sun himself became inactive, that is, ceased to revolve round his own axis; which revolution is, probably, one cause, not only of the revolution of the earth, but of all the other planetary bodies in our system, and might have effected all the planets at the time in question: but this neither could, nor did produce any disorder in nature; and the delay of a few hours in the whole planetary motions, dwindles away into an imperceptible point in the thousands of years of their revolutions. I need scarcely add, that the command of Joshua to the sun, is to be understood as a prayer to God (from whom the sun derived his being and continuance) that the effect might be what is expressed in the command; and therefore it is said, verse 14, ‘that the Lord hearkened unto the voice of a man, for the Lord fought for Israel.’”

How glorious an object is the sun! too dazzling for mortal eye long to gaze on: the brightest visible emblem of its adorable Creator. This luminary rejoices to run his prescribed course, makes our day joyful, and without his reviving beams we should dwell in perpetual darkness. He, as the great source of day, distributes light and life through all nature. Seeds, in the bosom of the earth, feel his vegetative presence, and unfold themselves. By his diffusive influence he causes the vital juice to ascend in the tubes of trees, plants, and vegetables; and clothes them with their various and beautiful foliage. He nourishes the young fruits, gives them their fine tints, and brings them to maturity. At his approach, millions of insects awake into life, shine, collect themselves, and sport in his rays. Animals partake of his benefits, and without his animating beams they would sink into insensibility and death: even in caves and dens of the earth, his visitation gives life. His heat has a pleasing effect on all the juices and fluids in the human body, which, without his directive or impulsive energy, would soon become stagnant and useless. He is, by the Divine wisdom and goodness, placed at such a proper distance from us, that, were he much nearer, the blood would boil in our veins, and our bodies soon be either dissolved or calcined: or, were he at a much greater distance, we should become torpid, and presently be congealed to statues of ice. The very bowels of the earth partake of his influence, thus producing many valuable and useful metals. He penetrates the highest mountains, though composed of stones and rocks. He darts his beams even into the depths of the ocean, where the watery tribes live and play at his command.

As the sun is the greatest visible glory in the natural world, so it is selected by the pen of Divine inspiration as the brightest emblem of the Supreme Being—“The Lord God is a sun.” This great luminary has been considered by the Heathen as the representative of the Deity, and as such received religious adoration. According to Mr. Bryant’s system of Ancient Mythology, the worship of fire is nearly as old as the flood, having been propagated by the posterity of Ham, in Egypt, who called themselves Ammonians, and carried this worship with them wherever they went, erecting their puratheia, or fire-temples, in all their settlements. It is stated, that fire was the primitive, or at least the principal object of idolatrous worship, and common to all idolaters from the first apostasy at Babel. For the original institution of this sacred fire among the Chaldeans, we must go back to Nimrod, concerning whom the Alexandrian Chronicon asserts, that “the Assyrians called Nimrod, Ninus; this man taught the Assyrians to worship fire.” From the Greeks we may trace it backwards to the Ur of the Chaldeans; on which the learned Classius remarks, that “Ur is the name of a city wherein the sacred fire was conserved and worshipped by the Chaldeans, whence it was called Ur, which otherwise signifies fire.” Plutarch confesses that the Romans, in the days of Numa, borrowed their worship of fire from the Greeks at Athens and Delphi. Numa built a temple of an orbicular form, to represent, as Plutarch interprets, the system of the heavens; which temple was the conservatory of a holy and perpetual fire, kindled at first by the reflections of the sun-beams, and placed in the centre of the building; the astronomy of that early period placing the sun in the centre of the world. Fire has such an affinity to light, that the same word has sometimes comprehended them both. The Ur of the Chaldeans was fire; the Horus of the Egyptians was light: and the reason is plain, because fire and light are united at the body of the sun, and by him diffused over the world. If, therefore, we consider fire as called into action by the sun, and bear in mind that the ancient Pythagoreans used the same term ΠΥΡ to denote both fire and the sun,116 we shall get at the root of most of the heathen mythologic divinity.

So universal was the attachment to this fire, that Macrobius undertook to reduce the names of all the heathen deities to the one object of the sun and its attributes. He says, “The Egyptians consecrated a lion in that part of the heavens where the heat of the sun is most powerful, because that animal seems to derive his nature from the sun, excelling all other creatures in fire and force, as the sun exceeds the other lights of heaven. His eyes, likewise, are bright and fiery, as the sun with a bright and fiery aspect surveys the world. The Lybians represented their Jupiter Hammon, which was the setting sun, with the horns of a ram, with which that animal exerts its strength, as the sun acts by its rays. The worship of Egypt abundantly shows, that the bull is to be referred to the sun; which is plain from the worship of a bull at Heliopolis, the city of the sun; and of the bull Apis at Memphis, where it was an emblem of the sun; and of the other bull called Pacis, consecrated in the magnificent temple of Apollo at Hermunthis.”117

Wheresoever fire was worshipped in the puratheia of antiquity after the manner of Numa, we may suppose that there the true solar system prevailed, which places the solar fire in the centre; and that this was really the universal opinion of the most ancient Heathens. This doctrine agrees with the name which they gave to the sun in his physical capacity, calling him cor cœli, the heart of the heaven;118 which illustration and allusion is probably of very great antiquity, because it cannot with any propriety be applied to the more modern Ptolemaic hypothesis. The analogy is very striking; for as the heart is the centre of the animal system, so is the sun in the centre of our world: as the heart is the fountain of the blood, so is the sun the source of light and fire: as the heart is the life of the body, so is the sun the life and heat of animated nature, and the first mover of the mundane system: when the heart ceases to beat, the circuit of life is at an end; and if the sun should cease to act, a total stagnation would take place throughout the whole frame of nature. Macrobius, pursuing this analogy, says, “We have before observed, that the sun is called the fountain of the ethereal fire; therefore the sun is in the heavens, what the heart is in animals.” Since the circulation of the blood has been known, this analogy has been taken up with advantage by the celebrated Hervey himself, who, first of all the moderns, explained to us with sufficient accuracy this branch of natural philosophy. He observes, that the heart of animals is the foundation of life, the chief ruler of all things in the animal system, the sun of the microcosm, from which flows all its strength and vigor. The philosophers of antiquity called the sun the heart of the microcosm; the moderns call the heart the sun of the microcosm. There must be something very striking in the analogy which is thus convertible, and has been taken up at both ends by such different persons, at such remote periods of time.

The savage philosophy of America seems to have comprehended in it the relation, which we have already noticed, between the animal system and the frame of nature. Acosta, in his History of the Indies, reports, that in the human sacrifices of the Mexicans, the high priest pulled out the heart with his hands, which he showed smoking to the sun, to whom he offered this heat and fume of the heart, and presently he turned towards the idol, and cast the heart at his face. A very highly esteemed correspondent in Ceylon writes, There is a cast of people inhabiting this island who live wild in the woods, and worship fire as an emblem of purity; they are called Vandals, and several English officers have met a premature death by intruding near the holy fire, which is under a tamarind tree.

With the Persians fire was an object of worship from the earliest times, under the name of Amanus, and Mithas; and it is retained as such at this day by the Geberrs, Gaurs, Guebres, or Ghebers, a sect of Indian philosophers. Pottinger says, “At the city of Yezd, in Persia, which is distinguished by the appellation of the Darûb Abadut, or seat of Religion, the Guebres are permitted to have an Atush Kudu, or Fire Temple (which, they assert, has had the sacred fire in it since the days of Zoroaster), in their own compartment of the city; but for this indulgence they are indebted to the avarice, not the tolerance of the Persian government, which taxes them at twenty-five rupees each man.” Hanway informs us, that the Ghebers suppose the throne of the Almighty is seated in the sun, and hence their worship of that luminary. “As to fire,” says Grose, “the Ghebers place the spring-head of it in that globe of fire, the sun, by them called Mithras, or Mihir, to which they pay the highest reverence, in gratitude for the manifold benefits flowing from his ministerial omniscience. But they are so far from confounding the subordination of the servant with the majesty of the Creator, that they not only attribute no sort of sense or reasoning to the sun or fire, in any of its operations, but consider it as a purely passive blind instrument, directed and governed by the immediate impression on it of the will of God; but they do not even give that luminary, all glorious as it is, more than the second rank among his works, reserving the first for the stupendous production of the Divine power, the mind of man.” The temples are generally built over subterraneous fires. Rabbi Benjamin observes, “Early in the morning, they (the Parsees or Ghebers of Ouham) go in crowds to pay their devotions to the sun, to whom upon all the altars are spheres consecrated, made by magic, resembling the circles of the sun; and, when the sun rises, these orbs seem to be inflamed, and turn round with a great noise. Every one has a censer in his hands, and offers incense to the sun.”

It is not a little surprising that the descendants of faithful Abraham, taken into covenant with God, should fall under the influence of this idolatrous worship! The apostasy of the Israelites in the wilderness from the true God to the golden calf, was occasioned by a previous attachment to the sacred rites of the Egyptian idolatry. And the calves which were afterwards set up in Dan and Bethel, were probably derived from the same source. The Israelites were not only cautioned against this worship, but, if the charge of idolatry brought against an Israelite was proved by unequivocal facts and competent witnesses, it affected his life. Such was the progress of this idolatrous worship among this people at one period, that Josiah, king of Judah, took away out of the temple of the Lord the horses, and burned the chariots, which the kings, his predecessors, had consecrated to the sun. Job, in allusion to this vile worship, says, “If I beheld the sun when it shined, or the moon walking in brightness; if my heart hath been secretly enticed, or my mouth hath kissed my hand:119 this also were an iniquity to be punished by the judge: for I should have denied the God that is above.” Ezekiel, in a vision, saw “at the door of the temple of the Lord, between the porch and the altar, about five and twenty men, with their backs toward the temple of the Lord, and their faces toward the east: and they worshipped the sun toward the east,” in imitation of the Egyptians, Persians, and other Eastern nations.

While the heathen have thus paid idolatrous worship to the sun, some persons, believing in the truth of revealed religion, have entertained strange notions concerning this luminary. It is remarkable, observes a polite writer, that whilst some of the ancients imagined the sun to be the seat of future blessedness, from Psal. xix, 14, “He set his tabernacle in the sun,” a Mr. Swinden, among the moderns, endeavors to prove that hell is seated in the sun, chiefly pleading that this is the grand repository of fire; that its horrible face, viewed by a telescope, suits the description given of the burning lake; and that being in the centre of the system, it might be properly said that wicked men were cast down into it. But these are mere hypotheses, and unworthy of serious consideration.

Notwithstanding this idolatrous worship of the sun, there is a sober and religious use to be made of this luminary; for being the greatest visible glory in the natural world it is selected as the brightest emblem of the Supreme Being—“The Lord God is a sun.” An object thus illustrious and useful in the regular and wise economy of nature, is mentioned in the sacred volume as a metaphor fraught with truths of infinite moment, imparting wisdom to the simple, and instruction to the ignorant. He admirably represents the unity, glory, and bounty of God.

Viewing our sun in all his paramount qualities to every material object in nature, how is he eclipsed and surpassed by the Sun of Righteousness, of whose splendor, grace, and energy this is but a faint emblem, and from whom issues, in bright and gentle beams, all the light, life, joy, and hope received and enjoyed in the Christian world. The one is the most magnificent creature among the vast variety of objects which surround us, but the other is the source of all that is excellent, attractive, and beneficial, in the whole range of material causes and effects, as well as in the nature, extent, and perpetuity of the kingdom of grace. The material sun runs its course from day to day, with unwearied regularity, activity, and ardor, and thus completes its circuit according to its original destination. And did not our adorable Saviour also finish the great career of our redemption, after he held performed all those miracles, and published his own everlasting gospel, which are the sublime and interesting themes of the sacred writers, by offering himself on the consecrated altar a sacrifice for the sins of mankind? The former diffuses light, vitality, vegetation, and felicity through the whole mass of animated nature in our planetary system. And does not the other likewise dissipate the ignorance which darkens the intellectual regions, enlighten our minds in all saving knowledge, and produce in the human heart every grace and virtue?

Were our natural sun to withdraw his beams, or absent himself from the centre of our system for any given time, the planets would start out of their orbits; darkness, black as night, would instantly spread itself over the whole mass, and “chaos come again.” And if the glorious Luminary of the moral world were to hide his face behind a thick cloud of gathering vengeance and judicial desertion, this would introduce into the soul alarming fears and tumultuous passions, which would exist in a state of opposition and conflict. Those who have been brought out of the darkness of ignorance, wickedness and misery, into the light of knowledge, holiness and happiness, by Christ, who is the light of the world, should be careful to walk in the light of his countenance all the days of their life. Does not the earth return the fructifying warmth of the sun, and all his genial effects, in a profusion of verdure, foliage, and flowers? Do not all the irrational tribes joyfully greet his rising every morning, and bask in his presence through the day with great delight? All the orbs which revolve round him, and are preserved and cherished in their respective spheres by his ministry, pay him perpetual homage by maintaining invariable harmony and order. And being thus taught by natural objects, what is due for the reception of so many mercies, surely it is an unquestionable duty that we guard against every thing which would prevent us doing the will of our best benefactor.

Christian believers, rich in the bloom of holiness, and ripening for the harvest of glory, are said to be “clothed with the sun.” It is the gracious promise, on which all their hopes and wishes confidently rely, that the “righteous shall” ultimately “shine as the sun in the kingdom of their Father.”120 Thus it is written, “The path of the just is as the shining light, that shines more and more unto the perfect day.” In the path of the just there is a progress from a less to a greater light: it does not only grow clearer, but increases in clearness till it is light in perfection; advancing from the break of day to the sun rising, and then to the brightness of noon-day.

Section II.—The Moon.

Names — Dimensions — Motions — Seasons — Phases — Harvest Moon — Moon’s Surface — Aërial Stones — Eclipses — Moonlight — Epithets — Religious Improvement.

The moon is called a great light, but less than the sun. Moses does not here speak philosophically, according to her bulk, but to the proportion of light she affords us, which is more than all the planets in the solar system and all the fixed stars put together.

The moon is not a primary planet, but only a satellite, or secondary planet, attendant on our earth, round which she revolves, and along with which she is carried round the sun.

“The moon,” says Dr. O. Gregory, “is a dark, or opake body, shining principally with the light she receives from the sun. If she shone by a light of her own, we should feel a sensible warmth from her rays; but it is a light reflected from the sun with which she shines, and is so exceedingly weak and languid, that the greatest burning glass will not collect enough to make any sensible degree of heat. This has been accounted for, and those who have gone through the computation assert that the light of the full moon is ninety thousand times less than day-light.” The ancients early discovered, that the moon had no light of its own, but shone with that which it reflected from the sun. This, after Thales, was the sentiment of Anaxagoras and Empedocles, who thence accounted not only for the mildness of its splendor, but the imperceptibility of its heat, which our experiments confirm.

In the Hebrew language the moon is called ירה Yarah, or, more strictly speaking, says Parkhurst, the lunar light, or flux of light, reflected from the moon’s body, or orb. That this is the true sense of the word is evident from several passages of Scripture, one of which is, “For the precious (produce) נרש ירחים put forth by—what? Not the orbs of the moon surely (for the orb is but one), but by the fluxes or streams of light reflected from it, which are not only several but various, according to the moon’s different phases and aspects in regard to the sun and the earth. And this may lead us to the radical idea of the word ירח; for as יחר and אחר,‎ יחד and אתד &c., are very nearly related to each other respectively, so likewise I conjecture that ירח is to ארה, in sense as well as in sound, and consequently that it signifies to go in a track or in a constant customary road or way; and this affords us a good descriptive name of the lunar light; for, Behold, says Bildad in Job, chap. xxv, 5, even to the ירח or lunar light ולא יאהיל and he (God) hath not pitched a tent (for it); as he has for the שמש or solar light. No! The lunar stream has fixed station from whence it issues, but together with the orb which reflects it, and which like a human traveller moves now a quicker, now a slower pace, is continually performing its appointed journey, and proceeding in a constant, though regularly irregular track.”

The Greeks called the moon μηνη, which may be considered as a derivative from μην. Parkhurst says, This word may be derived either from μηνη, the moon, by the phases of which the month is reckoned, or else it may be deduced from the Hebrew מנה manah, to number, compute, as being computed by the lunar phases. And it is probable that the first computations of time were made by the revolutions of the moon. It is obvious to remark, that not only these two Greek words, but also the Latin mensis, a month, and the English moon, month, are ultimately derived from the same Hebrew מנה. Leigh observes, that “the Hebrews call the moon and a month by the same name, because the moon is renewed every month. The Greeks also call σεληνη, from σελας, because it every day renews its light.” Parkhurst on the word σεληνη says, “The Greek etymologists, and particularly Plato, deduce it from σελας νεον, new light, because its light is continually renewed.” But the learned Goguet says; “The Greeks gave to the moon the name selene, which comes from the Phœnician word (לן or לון namely) which signifies to pass the night; whence also we may observe is plainly derived the Latin name of the moon, luna.” From lun with the termination a, comes luna, and this name is given to the planet from her changing or appearing under different phases.

As to the dimensions of the moon, according to the most accurate calculations, her diameter is 2,175 miles, the circumference 6,831 miles, the surface contains 14,898,750 square miles, and its solidity 5,408,246,000 cubical ones. Her bulk is equal to about a fiftieth part of our earth, and her mean distance from the earth is about 240,000 miles.

The motions of the moon are most of them very irregular. The only equable motion she has, is her revolution on her own axis. The time in which she moves round her axis is about 27 days, 7 hours, 43 minutes, 5 seconds; and her revolution through an elliptical orbit is performed in the same time as her rotation on her axis, moving about 2,290 miles every hour. Her revolution round her axis exactly in the same time that she goes round the earth, is the reason she always turns the same face towards us: she has only one day and one night in the course of a month. From a long series of observations, it has been ascertained that the moon makes a complete revolution in 27 days, 7 hours, 43 minutes, 5 seconds; this is called the periodical month; but, if we refer to the time passed from new moon to new moon again, the month consists of 29 days, 12 hours, and 44 minutes, which is called the synodical month. This difference is occasioned by the earth’s annual motion in its orbit. Thus, if the earth had no motion, the moon would make a complete round in 27 days, 7 hours, 43 minutes, and 5 seconds; but while the moon is describing her journey the earth has passed through nearly a twelfth part of its orbit, which the moon must also describe before the two bodies come again into the same position that they before held with respect to the sun: this takes up so much more time as to make her synodical month equal to 29 days, 12 hours, and 44 minutes. The motions of the hour and minute hands of a watch may serve to give some idea of the periodical and synodical revolutions of the moon; for when the minute hand has performed a complete revolution, it has yet some distance to go to obtain a coincidence with the hour hand, similar to that which it had the preceding hour.

We have observed that the same face is turned towards us during the whole of the moon’s revolution, and that the other half of her surface is never visible to us. This arises from the two motions we have noticed, which, with regard to our view of the moon, appear to counteract each other. Her revolution round the earth is performed towards the east; while the revolution upon her own axis is performed towards the west: so that, one of these motions turns as much of her face from us, as the other turns towards us. And from the moon’s axis being inclined to the plane of her orbit, sometimes one of her poles is inclined towards the earth, and sometimes the other: in consequence of which, we see more or less of her polar regions in different periods of her revolution. When the moon is in perigee, or nearest distance from the earth, her motion is quickest; and when in apogee, or most remote distance, her motion is slowest.

The length of the day is equal to our lunar month, for all that time is included in one revolution round her axis. Her days and nights, therefore, will constantly be of the same length, or almost fifteen of our days each. The year will be exactly the same with our year; because, being an attendant on the earth, she must go round the sun in the same time as that does. Her difference of seasons will be much less than on our earth, having only a small inclination of her axis of six degrees and a half; so that the variation between her summer’s heat and her winter’s cold must be comparatively inconsiderable. Hence there will be only thirteen degrees of Torrid Zone, on some parts most opposite the sun, and thirteen degrees of Frigid Zone on those contiguous to her poles; which consequently must leave seventy-seven degrees for what we should call her Temperate Zones, both in the north and south parts from her Equator. Our earth, unquestionably, performs the office of a moon to the moon, waxing and waning regularly, but appearing thirteen times as large, and, of course, affording her thirteen times as much light as she does to us. When she changes to us, the earth appears full to her; when she is in her first quarter to us, the earth is in its third quarter to her; and vice versâ. To the moon the earth seems to be the largest body in the universe, and must indeed be a most magnificent sight.

On the supposition that the moon is inhabited, it may be observed, that those who are placed about the middle of the surface, or face next to us, will constantly see our earth over their heads, and increasing and decreasing in light, like as the moon itself appears to us. Those who are situated near the borders, whether on the right or left, or upon the top or bottom, will also constantly have the same appearance in the opposite part of the horizon. But those who live on the side of the moon which is not presented to us, will know nothing of our earth, or at least, they will never have an opportunity of seeing this large and wonderful moon, without travelling perhaps more than 1,500 of our miles on the surface of that luminary. To those who live on this side of the moon, or travel to it on any account, as we may pass from the northern into the southern hemisphere of our globe, the earth, indeed, when at full to them, will appear to be more than three times as broad as the moon does to us, and to communicate, as has been already mentioned, about thirteen times as much light to her, as she does to us when at the full.

The moon, possessing no native light, shines entirely by light received from the sun, and which is reflected to us from her surface. That half of her which is towards the sun is enlightened, and the other half is dark and invisible: hence, when she is between us and the sun, she disappears, because her dark side is then towards us. Whilst making her revolution round the heavens, she undergoes a continual change of appearance. She is sometimes on our meridian at midnight, and therefore in that part of the heavens which is opposite to the sun; when she appears with a face completely circular, which is called a full moon. As she moves eastward, a part of her dark side comes forward on the western side, and, in a little more than seven days, reaches to the meridian, at about six in the morning, having the appearance of a semi-circle, with the convex side turned towards the sun: this crescent gradually becomes more slender, till, about fourteen days after the full moon, being so near the sun, and in a line between that luminary and our earth, she is rendered invisible to us, from the superior splendor of that orb of light. About four days after this disappearance, she may be seen in the evening, a little to the eastward of the sun, in the form of a fine crescent,121 as before, but having her convex side turned from the sun. Travelling still towards the east, the crescent becomes wider; and when advanced to the meridian, about six in the evening, she again bears the appearance of a bright semi-circle, with the same difference that we observed of the crescent, that is, its convex side is now turned from the sun. Advancing still more eastward, the semi-circular moon widens into an oval shape, till at last, in about twenty-nine days and a half from the last opposition to the sun, she is again in the same situation, and appears a full moon.

The following account of the harvest moon, so called, taken from the Pantalogia, will no doubt be acceptable to the reader.—It is remarkable that the moon, during the week in which she is full about the time of harvest, rises sooner after sun-setting than she does in any other full moon week in the year. By this means, she affords an immediate supply of light after sun-set, which is very beneficial for the harvest and gathering in the fruits of the earth; and hence this full moon is distinguished from all the others in the year, by calling it the harvest-moon.

To conceive the reason of this phenomenon, it may first be considered, that the moon is always opposite to the sun when she is full; that she is full in the signs Pisces and Aries in our harvest months, those being the signs opposite to Virgo and Libra, the signs occupied by the sun about the same season; and because those parts of the ecliptic rise in a shorter space of time than others, as may easily be shown and illustrated by the celestial globe: consequently, when the moon is about her full in harvest, she rises with less difference of time, or more immediately after sun-set, than when she is full at other seasons of the year.

In our winter, the moon is in Pisces and Aries about the time of her first quarter, when she rises about noon; but her rising is not then noticed, because the sun is above the horizon. In spring, the moon is in Pisces and Aries about the time of her change; at which time, as she gives no light, and rises with the sun, her rising cannot be perceived. In summer, the moon is in Pisces and Aries about the time of her last quarter; and then, as she is on the decrease, and rises not till midnight, her rising usually passes unobserved. But in autumn, the moon is in Pisces and Aries at the time of her full, and rises soon after sun-set for several evenings successively; which makes her regular rising very conspicuous at that time of the year.

When the moon is viewed through a good telescope, there appear vast cavities and asperities on various parts of her face, some of them extremely resembling deep caverns and vallies, and others mountains.