Fig. I.
91. Under Fig. 3, are the names and characters of the twelve Signs of the Zodiac, which the Reader should be perfectly well acquainted with; so as to know the characters without seeing the names. Every Sign contains 30 degrees, as in the Circle bounding the Solar System; to which the characters of the Signs are set in their proper places.
The Comets.
92. The Comets are solid opaque bodies, with long transparent trains or tails, issuing from that side which is turned away from the Sun. They move about the Sun, in very excentric ellipses; and are of a much greater density than the Earth; for some of them are heated in every Period to such a degree, as would vitrify or dissipate any substance known to us. Sir Isaac Newton computed the heat of the Comet which appeared in the year 1680, when nearest the Sun, to be 2000 times hotter than red-hot iron, and that being thus heated, it must retain it’s heat until it comes round again, although it’s Period should be more than twenty thousand years; and it is computed to be only 575. The method of computing the heat of bodies, keeping at any known distance from the Sun, so far as their heat depends on the force of the Sun’s rays, is very easy; and shall be explained in the [eighth Chapter].
[PLATE I].
Fig. I.
They prove that the Orbits of the Planets are not solid.
The Periods only of three are known.
They prove the Stars to be at immense distances.
93. Part of the Paths of three Comets are delineated in the Scheme of the Solar System, and the years marked in which they made their appearance. It is believed, that there are at least 21 Comets belonging to our System, moving in all sorts of directions: and all those which have been observed, have moved through the ethereal Regions and the Orbits of the Planets without suffering the least sensible resistance in their motions; which plainly proves that the Planets do not move in solid Orbs. Of all the Comets, the Periods of the above-mentioned three only are known with any degree of certainty. The first of these Comets appeared in the years 1531, 1607, and 1682; and is expected to appear again in the year 1758, and every 75th year afterwards. The second of them appeared in 1532 and 1661, and may be expected to return in 1789 and every 129th year afterwards. The third, having last appeared in 1680, and it’s Period being no less than 575 years, cannot return until the year 2225. This Comet, at it’s greatest distance, is about 11 thousand two hundred millions of miles from the Sun; and at it’s least distance from the Sun’s center, which is 490,000 miles, is within less than a third part of the Sun’s semi-diameter from his surface. In that part of it’s Orbit which is nearest the Sun, it flies with the amazing swiftness of 880,000 miles in an hour; and the Sun, as seen from it, appears an hundred degrees in breadth; consequently, 40 thousand times as large as he appears to us. The astonishing length that this Comet runs out into empty Space, suggests to our minds an idea of the vast distance between the Sun and the nearest fixed Stars; of whose Attractions all the Comets must keep clear, to return periodically, and go round the Sun; and it shews us also, that the nearest Stars, which are probably those that seem the largest, are as big as our Sun, and of the same nature with him; otherwise, they could not appear so large and bright to us as they do at such an immense distance.
Inferences drawn from the above phenomena.
94. The extreme heat, the dense atmosphere, the gross vapours, the chaotic state of the Comets, seem at first sight to indicate them altogether unfit for the purposes of animal life, and a most miserable habitation for rational beings: and therefore [[17]]some are of opinion that they are so many hells for tormenting the damned with perpetual vicissitudes of heat and cold. But, when we consider, on the other hand, the infinite power and goodness of the Deity; the latter inclining, and the former enabling him to make creatures suited to all states and circumstances; that matter exists only for the sake of intelligence; and that wherever we find it, we always find it pregnant with life, or necessarily subservient thereto; the numberless species, the astonishing diversity of animals in earth, air, water, and even on other animals; every blade of grass, every tender leaf, every natural fluid, swarming with life; and every one of these enjoying such gratifications as the nature and state of each requires: when we reflect moreover that some centuries ago, till experience undeceived us, a great part of the Earth was judged uninhabitable; the Torrid Zone by reason of excessive heat, and the two Frigid Zones because of their intollerable cold; it seems highly probable, that such numerous and large masses of durable matter as the Comets are, however unlike they be to our Earth, are not destitute of beings capable of contemplating with wonder, and acknowledging with gratitude the wisdom, symmetry, and beauty of the Creation; which is more plainly to be observed in their extensive Tour through the Heavens, than in our more confined Circuit. If farther conjecture is permitted, may we not suppose them instrumental in recruiting the expended fuel of the Sun; and supplying the exhausted moisture of the Planets? However difficult it may be, circumstanced as we are, to find out their particular destination, this is an undoubted truth, that wherever the Deity exerts his power, there he also manifests his wisdom and goodness.
This System very ancient, and demonstrable.
95. THE SOLAR SYSTEM here described is not a late invention; for it was known and taught by the wise Samian philosopher Pythagoras, and others among the ancients; but in latter times was lost, ’till the 15th century, when it was again restored by the famous Polish philosopher Nicholaus Copernicus, who was born at Thorn in the year 1473. In this, he was followed by the greatest mathematicians and philosophers that have since lived; as Kepler, Galileo, Descartes, Gassendus, and Sir Isaac Newton; the last of whom has established this System on such an everlasting foundation of mathematical and physical demonstration, as can never be shaken: and none who understand him can hesitate about it.