immense, that the circle of the earth's annual orbit bears no greater proportion to it, than the center of any sphere bears to it's whole furface. Philolaus, and others, declared the motion of the fun, round about the earth, to be only apparent. They faw and felt the importance of his globe over our's, and fuppofing it's influence to extend to much larger bounds than that of the earth, they placed it in the center of the universe. Among the Romans, we find that Numa built a temple to reprefent, as Plutarch interprets it,* the system of the heavens, with a facred fire in the center of it. Thus alfo in the Jewish tabernacle, the feven lights had a reference to the feven chief lights of the heavens. Hence alfo the heavens are called in facred writ the tabernacle of the fun; the whole of our fyftem dwelling within his influence. The foregoing citations are, we prefume, fufficient to shew that the ancients were not ignorant of the true folar system. Those that want further information on this head, may confult the notes to Sydenham's tranflation of the Rivals of Plato, Duten's inquiries

* Plutarch in Vita Numæ.

+ Focum Veftæ virginibus colendum dedit, ur AD SIMILITUDINEM CELESTIUM SIDERUM cuftos imperii flamma vigilaret. Flor. Hift.

ries into the origin of the difcoveries attributed to the moderns; Jones's effay on the first principles of natural philofophy; Baillie hiftoire de l'aftronomie ancienne. But laying these authorities afide, there are direct proofs to fhew, that the moft ancient fages could not be ignorant of the true fyftem; thefe, however, must be left to fome other occafion.

We are greatly indebted to Copernicus for the revival of this fyftem, and being bold enough to avow it, though it was entirely opposed to the prejudices of the age he lived in. In praifing of Copernicus, let us not, however, endeavour to do away the well-earned fame of Ptolemy; his fyftem, though erroneous, was ingenious; with it the world was content for many ages. It was then confidered as founded upon invincible demonstration, as a facred truth, that could not be weakened by the powers of controverfy, or fhaken by the fluctuations of opinion. Being in poffeffion of higher truth, we fhould not speak degradingly of thofe who preceded us. If the, ground we stand on be firm, it will not need fupport from the empty boaftings of declamation, the authority of names, or the contemptuous fneers of an affected difdain: the writings of modern philofophers furnish but too many instan

ces

ces of the high opinion they entertain of their own knowledge, and their contempt of thofe who differ from them.

Let the young pupil be cautioned not to con fine the idea of bigotry to the fuperftitious zealots of religion; for he will find as much attachment to trifles, as much blind prejudice, and as little love to truth for truth's fake, among those who are called philofophers, as among the most inveterate fectarians, or the wildest fanatics.

Let him, therefore, early learn to distinguish the different degrees of evidence, of which each fubject is capable; but above all, let him ftudioufly avoid the improper conjunction of the demonstrative evidence of one fcience, with the bare probability, or unfounded affertions in another; left, like those who have gone before him, he should call that demonftrated, which is often not even probable.

Before we enter into a defcription of the fyftem, it may be neceffary to define what is meant by the axis of a planet; left the pupil fhould conceive them to turn on fuch material axes, as are used in the machines which are con trived to reprefent the planetary system.

The

The AXIS OF A PLANET is a line conceived to be drawn through it's center, and about which it continually turns, in the course of it's revolution round the fun: the extremities of this line terminate in oppofite points of the furface of the planet, and are called it's POLES; that which points towards the northern part of the heaven, is called the NORTH POLE; that which points towards the fouthern, the SOUTH POLE.

A ball whirled from the hand into the open air, turns round upon a line within itself, while it is moving forward; fuch a line as this is meant, when we speak of the axis of a planet.

Fig. 1, plate I. represents the folar system, wherein denotes the fun; A B the circle which the nearest planet, Mercury, describes in moving round it; CD that in which Venus moves; FG the orbit of the earth; HK that of Mars; IN that of Jupiter; OP that of Saturn; and QR that of the Georgium Sidus; beyond this are the ftarry heavens.

The fun and the planets are fometimes expreffed by marks or characters, instead of writing their names at length. The characters are as follow:

The fun is the center of the system, round which the rest of the planets revolve. It is the first and greatest object of aftronomical knowledge, and is alone enough to stamp a value on the science, to which the study of it belongs.

The fun is the parent of the feafons; day and night, fummer and winter, are among it's furprizing effects. All the vegetable creation are the offspring of it's beams; our own lives are fupported by it's influence. Nature revives, and puts on a new face, when it approaches nearer to us in fpring; and finks into a temporary death at his departure from us in the winter.

Hence it was, with propriety, called by the ancients COR COLI, the heart of heaven; for as the heart is the center of the animal system, so is the fun the center of our universe. As the heart is the fountain of the blood, and the center of heat and hotion; fo is the fun the life and heat of the world, and the first mover of the mundane fyftem. When the heart ceases to beat, the cir