THE PLANETARIUM, AND ASTRONOMICAL CALCULATOR. "Astronomy, Parent of Devotion! engage my midnight vigils, SECTION FIRST. OF ASTRONOMY IN GENERAL. Or all the sciences cultivated by mankind, Astronomy is acknowledged to be, and undoubtedly is, the most sublime, the most interesting, and the most useful. By the knowledge derived from this science, not only the magnitude of the earth is discovered, the situation and extent of the Countries and Kingdoms ascertained, trade and commerce carried on to the remotest parts of the world, and the various products of several countries distributed, for the health, comfort, and conveniency of its inhabitants; but our very faculties are enlarged, with the grandeur of the ideas it conveys, our minds exalted above the low contracted prejudices of the vulgar, and our understandings clearly convinced, and affected with the conviction, of the existence, wisdom, power, goodness, immutability, and superintendency of the Supreme Being. So that without any hyperbole, every man acquainted with this science, must exclaim with the immortal Dr. Young: "An undevout Astronomer is mad." From this branch of Mathematical knowledge, we also learn by what means, or laws, the Almighty Power and Wisdom of the Supreme Architect of the Universe, are administered in continuing the wonderful harmony, order and connexion, observable throughout the planetary system; and are led by very powerful arguments, to form this pleasing and cheering sentiment, that minds capable of such deep researches, not only derive their origin from that Adorable Being, but are also incited to aspire after a more perfect knowledge of his nature, and a more strict conformity to his will. By Astronomy we discover, that the earth is at so great a distance from the sun, that if seen from thence, it would appear no larger than a point; although its diameter is known to be nearly 8,000 miles: yet that distance is so small, compared with the earth's distance from the fixed stars, that if the orbit, in which the earth moves round the Sun, were solid, and seen from the nearest star, it would likewise appear no larger than a point; although it is at least 190 millions of miles in diameter; for the earth in going round the sun, is 190 millions of miles nearer to some of the stars, at one time of the year than at another; and yet their apparent magnitudes, situations, and distances, still remain the same; and a telescope which magnifies above 200 times, does not sensibly magnify them; which proves them to be at least, one hundred thousand times further from us, than we are from the sun. It is not to be imagined that all the stars are placed in one concave surface, so as to be equally distant from us; but that they are placed at immense distances from one another, through unlimited space, so that there may be as great a distance between any two neighbouring stars, as between the sun from which we receive our light, and those which are nearest to him. Therefore, an observer who is nearest any fixed star, will look upon it alone as a real sun; and consider the rest as so many shining points, placed at equal distances from him in the firmament. By the help of telescopes, we discover thousands of stars which are entirely invisible, without the aid of such instruments, and the better our glasses are, the more become visible. We therefore can set no limits to their numbers, or to their immeasurable distances. The celebrated Huygens carried his thoughts so far, as to believe it not impossible, that there may be stars at such inconceivable distances, that their light has not yet reached the earth since their creation; although the velocity of light, be a million of times greater than the velocity of a cannon ball at its first discharge; and as Mr. Addison justly observes, "This thought is far from being extravagant, when we consider that the Universe is the work of Infinite Power, prompted by Infinite Goodness, and having an Infinite space to exert itself in; therefore our finite imaginations can set no bounds to it." The Sun appears very bright and large, in comparison of the fixed stars; because we constantly keep near the Sun, in comparison to our immense distance from them. For a spectator placed as near to any star, as we are to the Sun, would see that star to be a body as large and bright as the Sun appears to us: and a spectator as far distant from the Sun, as we are from the stars, would see the sun as small as we see a star, divested of all its circumvolving planets, and would reckon it one of the stars, in numbering them. The stars being at such immense distances from the Sun, cannot possibly receive from him so strong a light as they appear to have, nor any brightness sufficient to make them visible to us; for the Sun's rays must be so scattered before they reach such remote objects, that they can never be transmitted back to our eyes; so as to render these objects visible by reflection. Therefore the stars, like the sun, shine with their own native and unborrowed lustre; and since each particular one, as well as the Sun, is confined to a particular portion of space, it is evident that the stars are of the same nature with the Sun; formed of similar materials, and are placed near the centres of as many magnificent systems; have a retinue of worlds inhabited by intelligent beings, revolving round them as their common centres; receive the distribution of their rays, and are illuminated by their beams; all of which, are lost to us, in immeasurable wilds of ether. |