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436
ASTRO furdity to imagine that the ftars were made for no other purpofe than to caft a faint light upon the earth; efpecially fince many more require the affiflance of a good tefefcope to find them out, than are vifible without that inflrument. Our fun is furrounded by a fyftem of planets and comets ; all which would be invifible from the neared fixed ftar. And from what we already know of the immenfe diftance of the liars, the neared may be computed at 32,000,000,000,000 of miles from us, which is farther than a cannon-bullet would fly in 7,000,000 of years. Hence it is eafy to prove, that the fun, feen from fuch a didance, would appear no bigger than a dar of the fird magnitude. From all this ft is highly probable, that each dar is a fun to a fyflem of worlds moving round it, though unfeen by us ; efpecially as the dodtrine of a plurality of worlds is rational, and greatly manifeds the power, wifdom, and goodnefs of the great Creator. The liars, on account of their apparently various magnitudes, have-been didributed into feveral dalles, or orders. Thofe which appear larged, are called Jiars of fke fitJl magnitude-, the next to them in ludre, fia^s of the fecond magnitude-, and fo on the fixth, which are the fmalled thjit are vifible to the bare eye. This diltribution having been made long before the.invention of telefcopes, the liars which cannot be feen without the aflidance of thefe inllrumerits, are didinguilhed by the name of telcfcipfc fan. The ancients divided the darry fphere into particular condellations, or fydems of dars, according as they lay near one another, fo as to occupy thofe dpaces which the figures of different forts of animals or things would take up, if they were there delineated. And thofe dars which could not be brought into any particular condellation, were called unformed Jiars. This drvifion of the darj into different condellations or aderifms, ferves to didinguilh them from one another, fo that any particular dar may be readily found in the heavens by means of a celedial globe; on which the condellations are fo delineated, as to put the mod remarkable dars into fuch parts of the figures as are mod eafily didinguilhedj The number of the ancient condellations is 48, and upon our prefent globes about 70. On Senex’s globes are inferted Bayer’s letters; the fird in the Greek alphabet being put to the bigged dar in each conflellation, the fecond to the next, and fo on : By which The, ancient Condellations. Uffa minor The Little Bear Urfa major The Great Bear Draco The Dragon Gepheus Gepheus Bootes, Arftophilax The Northern Crown Corona Borealis Hercules* Engonajin Hercules kneeling The Harp Lyra Cygnus, Gallina The Swan The Lady in her Chair’ Caffiopea Perfeus Perfeus The Waggoner Auriga Serpentariusg Ophiuchus Serpentarius
N O M Y. means, every dar is as eafily found as if a name were given to it. Thus, if the dar y in the condellation of the ram be mentioned, every adronomer knows as well what dar is meant as if it were pointed out to.him in the heavens. There is alfo a divifion of the heavens into three parts. 1. The Zodiak from tyj'tov, zodion, an animal, becaufe mod of the condellations in it, which are twelve in number, are the figures of animals: As dries the ram, faurus the bull, Gemini the twins, Cancer the crab, Leo the lion, Virgo the virgin, Libra the balance, Scorpio the fcorpion, Sagittarius the archer, Capricor-nus the goat, Aquarius the water-bearer, and Pifces the fifties. The zodiac goes quite round the heavens r it is about 16 degrees broad, fo that it takes in the orbits, of all the planets, and likewife the orbit of the moon. Along the middle of this zone or belt is the ecliptic, or circle which the earth defcribes annually as feen from the fun ; and which the fun appears to defcribe as feen from the earth. 2. All that region of the heavens, which is on the north fide of thd zodiac, containing twenty-one condellations. And, 3. That on the fouth fide, containing fifteen. The ancients divided the zodiac into the above twelve condellations or figns in the following manner. They took a veffel with a fmall hole in the bottom, and having filled it with water, differed the fame to didil drop by drop into another veffel fet beneath to receive it; beginning at the moment when fome dar rofe, and continuing until it rofe the next following night. The water fallen down into the receiver they divided into twelve equal parts; and having two other fmall veffels in readinefs, each of them fit to contain one part, they again poured all the water into the upper veffel, and obierving the rifing of fome dar in the zodiac, they at the fame time differed the water to drop into one of the fmall veffels; and as foon as it was full, they' ftiifted it, and fet an empty one in Its place. When each veffel was full, they took notice what dar of the zodiac rofe ; and though this could not be done in one night, yet in many they obferved the rifing of twelve dars or points, by which they divided the zodiac into twelve parts. The names of the condellations, and the number of dars obferved in each of them by different adronomers, are as follow. Ptolemy. 8 35 3* 213 38 „ 29 10 W 13 29 14 29
Tycho. 7 , 29 32 184 18 2<$ 29 9 15
51 528 45
- 7
47 37 46 40 49
Flamfieed. 8724 80 35 54 81 55 59 66 74
Serpens
