of a telescope, contains no more than three thousand in both hemispheres.

As we have incomparably more light from the Moon, than from all the stars together, it is the greatest absurdity to imagine, that the stars were made for no other purpose than to cast a faint light upon the earth; especially, since many more require the assistance of a good telescope to find them out, than are visible without that instrument. Our Sun is surrounded by a system of planets, and comets, all of which would be invisible from the nearest fixed star: And, from what we already know of the immense distance of the stars, the nearest may be computed at 32 billions of miles from us, which is farther than a cannon ball can fly in 7 millions of years, though it proceeded with the same velocity as at its first discharge. Hence it is easy to prove, that the Sun, seen from such a distance would appear no larger than a star of the first magnitude. From the foregoing observations it is highly probable, that each star is the centre of a magnificent system of worlds, moving round it, though unseen by us, and are irradiated by its beams: especially, as the doctrine of plurarity of worlds is rational, and greatly manifests the power, wisdom and goodness of the great Creator.

The stars, on account of their apparently various magnitudes have been distributed into several classes, or orders. Those which appear largest are called stars of the first magnitude, the next to them in lustre, stars of the second magnitude, and so on to the sixth, which are the smallest that are visible to the unaided sight.

This distribution, having been made long before the invention of telescopes, the stars which cannot be seen without the assistance of these instruments, are distinguished by the name of telescopic stars..

The ancients divided the starry spheres into particular constellations, or systems of stars, according as they lay near each other, so as to occupy those spaces which the figures of different sorts of animals, or things would take up, if they were there delineated. And those stars which could not be brought into any particular constellation, were called unformed stars.

This division into different constellations or asterisms, serves to distinguish them from each other; so that any particular star may be readily found in the Heavens, by means of a celestial globe, on which the constellations are so delineated, as to put the most remarkable stars into such parts of the figures, as are most easily distinguished. The number of ancient constellations is 48, and upon our present globes, about 70. There is also a division of the Heavens into three parts. First the Zodiac, signifying an animal, because most of the constellations in it, which are twelve in number, are the figures of animals, as Aries, the ram, Taurus, the bull, Gemini, the twins, Cancer, the crab, Leo, the lion. Virgo, the virgin, Libra, the balance, Scorpio, the scorpion, Sagitarius, the archer, Capricornus, the goat, Aquarius, the water-bearer, and Pisces, the fishes.--· The Zodiac goes quite ronnd the Heavens, it is about 16 degrees broad, so that it takes in the orbits of the Moon, and of all the planets, (excepting that of Pallas,

and the satellites of Herschel.) Along the middle of this zone, or belt, is the ecliptic, or circle which the earth describes annually, as seen from the Sun, and which the Sun appears to describe as seen from the earth. Second. All that region of the Heavens which is on the north side of the Zodiac, containing 21 con stellations: And, Third, that region on the south side of the Zodiac, containing 15 constellations.

There is a remarkable track around the Heavens, called the Galaxy, or Milky Way from its peculiar whiteness. It was formerly thought to be owing to a vast number of very small stars, closely connected,and the observation of Dr. Herschel have fully confirmed the opinion. He therefore considers the Galaxy as a very extensive branching congeries of many millions of stars, which probably owes its origin to several remarkable large, as well as very closely scattered small stars, that may have drawn together the rest,

ON GROUPS OF STARS.

Groups of Stars, succeed to clustering Stars in Dr. Herschel's arrangement. A group is a collection of Stars, closely, and almost equally compressed,, and of any figure or outline. There is no particular condensation of the Stars to indicate the existence of a central force, and thegroups are sufficiently separated from neighboring Stars, to show that they form peculiar systems of theirown.

ON CLUSTERS OF STARS.

Dr. Herschel regards Clusters of Stars as the most magnificent objects in the Heavens. They differ from groups in their beautiful and artificial arrangement.Their form is generally round, and their condensation is such as to produce a mottled lustre, somewhat resembling a nucleus. The whole appearance of a cluster indicates the existence of a central force, residing either in a central body, or in the centre of gravity of the whole system.

Interrogations for Section Eighteenth.

What is a fixed Star?

Why do they appear of sensible magnitude to the eye?

Do the Stars appear larger when viewed through a telescope, than viewed with the eye only?

What does it prove ?

Which appear the largest, the satellites of Jupiter, or the Stars, when viewed with a telescope?

About how many Stars in a clear night can be seen by the naked eye ?

How many in the British catalogue?

Are some of that number telescopic?

Would the planets and comets of the Solar System be invisible from the nearest Star?

At how many miles distant may we with propriety, suppose the nearest fixed Star?