of its orbit nearest the star, than it seemed to be when the earth was at the moft diftant part of its orbit, or 190 millions of miles farther removed from the fame ftar. The ftar neareft us, and confequently the largest in appearance, is the dog-ftar, or Sirius. Modern difcoveries make it probable that each of thofe fixed ftars is a fun, having planets and comets revolving round it, as our fun has the earth and other planets revolving round him. Now the dog-itar appears 27,000 times lefs than the fun : and, as the diftance of the ftars must be greater in proportion as they feem lefs, mathematicians have computed the diftance of Sirius from us to be two billions and two hundred thousand millions of miles. A ray of light, therefore, though its motion is fo quick as to be commonly thought inftantaneous, takes up more time in travelling from the stars to us than we do in making a Weft-India voyage. A found, which, next to light, is confidered as the quickest body we are acquainted with, would not arrive to us from thence în 50,000 years. And a cannon-ball, flying at the rate of 480 miles an hour, would not reach us in 700,000 years.

The ftars, being at fuch immenfe diftances from the fun, cannot poffibly receive from him fo ftrong a light as they feem to have, nor any brightness fufficient to make them vifible to us. For the fun's rays must be fo fcattered and diffipated before they reach fuch remote objects, that they can never be tranfmitted back to our eyes, fo as to render those objects vifible by reflection. The stars, therefore, fhine with their own native and unborrowed luftre, as the fun does; and fince each particular ftar, as well as the fun, is confined to a particular portion of space, it is evident that the ftars are of the fame nature with the fun.

It is far from probable that the Almighty, who always acts with infinite wisdom, and does nothing in vain, thould create so many glorious funs, fit for fo many important purpofes, and place them at fuch diftances from each other, without proper objects near enough to be benefited by their influences. Whoever imagines that they were created only to give a faint glimmering light to the inhabitants of this globe, muft have a very fuperficial knowledge of aftronomy, and a mean opinion of the divine wifdem; fince, by an infinitely lefs exertion of creating power, the Deity could have given our earth much more light by one fingle additional

moon.

Inftead then of one fun and one world only, in the universe, as the unfkilful in aftronomy imagine, that fcience difcovers to us fuch an incon ceivable number of funs, fyftemis, and worlds, difperfed through boundlefs fpace, that if our fun, with all the planets, moons, and comets belonging to it, were annihilated, they would be no more miffed by an eye that could take in the whole creation, than a grain of fand' from the feafhore; the space they poffefs being comparatively fo fmall, that it would fcarcely be a fenfible blank in the univerfe, although the Georgium Sidus, the outermoft of our planets, revolves about the fun in an orbit of 10,830 millions of miles in circumference,, and fome of our comets make excurfions upwards of ten thousand millions of miles beyond the orbit of the Georgium Sidus; and yet, at that amazing diftance, they are incomparably nearer to the fun than to any of the stars, as is evident from their keeping clear of the attracting power of all the ftars, and returning periodically by virtue of the fun's attraction.

*Efpecially fince there are many ftars which are not visible without the affiftance of a good telescope; and, therefore, instead of giving light to this world, can only be íeen by a few aftronomers.

From what we know of our own system, it may be reasonably concluded that all the reft are with equal wisdom contrived, fituated, and provided with accommodations for rational inhabitants. For although there is an almost infinite variety in the parts of the creation which we have opportunities of examining, yet there is a general analogy running through and connecting all the parts into one scheme, one defign, one whole.

Since the fixed ftars are prodigious fpheres of fire, like our fun, and at inconceivable distances from each other as well as from us, it is reasonable to conclude they are made for the fame purposes that the fun is, each to beftow light, heat, and vegetation, on a certain number of inhabited planets, retained by gravitation within the fphere of its activity.

What a fublime idea does this fuggeft to the human imagination, limited as are its powers, of the works of the Creator! Thousands and thousands of funs, multiplied without end, and ranged all around us, at immense distances from each other, attended by ten thousand times ten thousand worlds, all in rapid motion, yet calm, regular and harmonious, invariably keeping the paths prescribed them: and thefe worlds peopled with myriads of intelligent beings, formed for endless progreffion in perfection and felicity!

If fo much power, wifdom, goodness, and magnificence, is difplayed in the material creation, which is the leaft confiderable part of the univerfe, how great, how wife, how good, muft HE be, who made and governs the whole!

THE CONSTELLATIONS.] The first people who gave much attention to the fixed ftars, were the shepherds in the beautiful plains of Egypt and Babylon; who, partly for amufement, and partly with a view to direct them in travelling during the night, obferved the fituation of these ce. leftial bodies. Endowed with a lively fancy, they divided the stars into different affemblages or conftellations, each of which they fuppofed to reprefent the image of fome animal, or other terreftrial object. The peasants in our own country do the fame, for they diftinguish that great northern conftellation, which aftronomers call Urfa Major, by the name of the Plough, the figure of which it certainly may reprefent, with a very little aid from the fancy. The conftellations in general have preserved the names which were given them by the ancients; by whom they were reckoned 21 northern and 12 fouthern but the moderns have increased the number of the northern to 36, and that of the fouthern to 32. Befides thefe, there are the 12 figns or conftellations in the Zodiac, as it is called from the Greek word wev, an animal, because each of these 12 is supposed to reprefent fome animal. This is a great circle which divides the heavens into two equal parts, of which we fhall speak hereafter. In the mean time we fhall conclude this fection with an account of the rife and progress of aftronomy, and the revolutions which have taken place in that science.

:

DIFFERENT SYSTEMS OF THE UNIVERSE.] Mankind must have made a very confiderable improvement in obferving the motions of the heavenly bodies, before they could fo far difengage themfelves from the prejudices of fenfe and popular opinion, as to believe that the earth upon which we live was not fixed and immoveable. We find, accordingly, that Thales, the Milefian, who, about 580 years before Chrift, firft taught aftronomy in Europe, had made a fufficient progrefs in this fcience to calculate eclipfes, or interpofitions of the moon between the earth and the fun, or of the earth between the fun and the moon (the nature of which may be easily understood from what we have already obferved). Pythagoras, a native

of Samos, flourished about 50 years after Thales, and was, no doubt. equally well acquainted with the motion of the heavenly bodies. He conceived an idea, which there is no reason to believe had ever been thought of before, namely, that the earth itself was in motion, and that, the fun was at reft. He found that it was impoffible, in any other way, to explain confiftently the heavenly motions. His fyftem, however, was fo extremely oppofite to all the prejudices of fenfe and opinion, that it never made great progrefs, nor was ever widely diffused in the ancient world. The philofophers of antiquity, defpairing of being able to overcome ignorance by reafon, endeavoured to adapt the one to the other, and in fome meafure to reconcile them. Ptolemy, an Egyptian philofopher, who flourished 138 years before Chrift, fuppofed, with the vulgar. that the earth was fixed immoveably in the centre of the univerfe, and that the feven planets, confidering the moon as one of the primaries, were placed near to it. Above them he placed the firmament of fixed stars, then the cryftalline orbs, then the primum mobile, and last of all, the cœlum empyreum, or heaven of heavens. All these vaft orbs he imagined to move round the earth once in 24 hours, and, besides that, in certain ftated and periodical times. To account for these motions, he was obliged to conceive a number of circles, called eccentrics and epicycles, croffing and interfering with each other. This fyftem was univerfally maintained by the peripatetic philofophers, who were the moft confiderable fect in Europe, from the time of Ptolemy to the revival of learning in the fixteenth century.

At length, Copernicus, a native of Poland, a bold and original genius, adopted the Pythagorean or true fyftem of the univerfe, and publifhed it to the world in the year 1530. This doctrine had remained fo long in obfcurity, that the reftorer of it was confidered as the inventor; and the fyftem obtained the name of the Copernican philofophy, though only revived by that great man.

Europe, however, was ftill immersed in ignorance; and the general ideas of the world were not able to keep pace with thofe of a refined philofophy. Copernicus therefore had few abettors, but many opponents. Tycho Brahe, in particular, a noble Dane, fenfible of the defects of the Ptolemaic fyftem, but unwilling to acknowledge the motion of the earth, endeavoured, about the year 1586, to establish a new fyftem of his own, which was ftill more perplexed and embarraffed than that of Ptolemy. It allows a monthly motion to the moon round the earth, as the centre of its orbit; and makes the fun to be the centre of the orbits of Mercury, Venus, Mars, Jupiter, and Saturn. The fun, however, with all the planets, is fuppofed to be whirled round the earth in a year, and even once in the twenty-four hours. This fyftem, notwithstanding its abfurdity, met with many advocates- Longomontanus, and others, fo far refined upon it, as to admit the diurnal motion of the earth, though they infifted that it had no annual motion.

About this time, after a darkness of many fucceffive ages, the fi dawn of learning and tafte began to appear in Europe. Learned men in different countries began to cultivate aftronomy. Galileo, a Florentine, about the year 1610, introduced the ufe of telescopes, which furnished new arguments in fupport of the motion of the earth, and confirmed the old ones. The fury and bigotry of the clergy, indeed, had almost ftifled the fcience in its infancy; and Galileo was obliged to renounce the Copernican fyftem, as a damnable herefy. The happy re

the reach of the papal thunder. It taught mankind that the Scriptures were not given for explaining fyftems of natural philofophy, but for a much nobler purpofe,-to render us juft, virtuous, and humane; that, inftead of oppofing the word of God, which, in speaking of natural things, fuits itself to the prejudices of weak mortals, we employed our faculties in a manner highly agreeable to our Maker, in tracing the nature of his works, which, the more they are confidered, afford us the greater reason to admire his glorious attributes of power, wisdom, and goodness. From this time, therefore, noble discoveries were made in all the branches of aftronomy. Not only the motions of the heavenly bodies were clearly explained, but the general law of nature, according to which they moved, was difcovered and illuftrated by the immortal Newton. This law is called Gravity or Attraction, and is the fame by which any body falls to the ground, when difengaged from what fupported it. It has been demonftrated, that this fame law, which keeps the fea in its channel, and the various bodies which cover the furface of this earth from flying off into the air, operates throughout the universe, retains the planets in their orbits, and preferves the whole fabric of nature from confufion and diforder.

SECT. II.

OF THE SPHERE.

HAVING, in the foregoing fection, treated of the UNIVERSE in gene

ral, in which the earth has been confidered as a planet, we now proceed to the doctrine of the SPHERE, which ought always to precede that of the globe or earth, as we shall fee in the next tection. In treating this subject we shall confider the earth as at reft, and the heavenly bodies as performing their revolutions around it. This method cannot lead the reader into any mistake, fince we have previously explained the true fyftem of the univerfe, from which it appears, that it is the real motion of the earth which occafions the apparent motion of the heavenly bodies. It is befides attended with this advantage, that it perfectly agrees with the information of our fenfes. The imagination therefore is not put on the ftretch; the idea is easy and familiar; and, in delivering the elements of fcience, this object cannot be too much attended to.

N. B. In order more clearly to comprehend what follows, the reader may occafionally turn his eye to the figure of the artificial sphere on the oppofite page.

The ancients obferved, that all the ftars turned (in appearance) round the earth, from east to west, in twenty-four hours; that the circles which they defcribed in those revolutions were parallel to cach other, but not of the fame magnitude; those palling over the middle of the earth be ing the largest, while the reft diminished in proportion to their distance from it. They also obferved, that there were two points in the heavens which always preferved the fame fituation. Thefe points they termed celeftial poles, because the heavens feemed to turn round them. In order to imitate thefe motions, they invented what is called the Artificial Sphere, through the centre of which they drew a wire or iron red, called an Aris, whofe extremities were fixed to the immoveable points called Poles. They further obferved, that, on the 20th of March and