A

Zodiacal Light is a faint luminous appearance, which accomthe Sun, and is seen just after twilight in the evening, or before mences in the morning. It was observed by KEPLER, who supit to be the Sun's atmosphere, and afterwards accurately described SSINI, in 1683, who gave it the name by which it is now known, sequence of its always being in the ZODIAC. It probably surs the sun on all sides; but is shaped like a lens, or burning glass, cumference of which is directly over the Sun's equator. The edge always presented to us, gives it the appearance of a pyramid, or There can only that portion of it be seen which remains above orizon after twilight has ceased. When seen, it extends from the n upwards, and following the course or path of the Sun. For eason it is scarcely visible in our latitude, as the path of the Sun g most of the year, is very oblique to the horizon: consequently bscured by twilight, which does not cease until the Sun is 18 es below the horizon. At the equator it can be favorably observed of the year, and often presents a beautiful appearance. The favorable times for observing it in our latitude are in the evening g the months of April and May, and in the morning during the as of October and November, as the path of the sun is nearer ndicular to the horizon than at any other times during the year.

It appears in form like a pyramid, with the base at the ho tapering to a point, and more or less inclined to the horizon.

Its length above the horizon varies, according to circumstan 40 to 100 degrees, and its breadth at the base perpendicular to varies from 8 to 30 degrees. It is extremely faint and ill-de our climate; but is much more conspicuous in tropical countri allusion is made to this phenomenon in a work published by drey, in 1661, in the following passage: - "In the month of Fe for several years, about six o'clock in the evening, after twiligh a path of light tending from the twilight towards the Pleiades, as touching them: this is to be seen whenever the weather is cl best when the moon does not shine. I believe that this phen has been before visible, and will hereafter appear, always at the mentioned period of the year; but the cause and nature of it I guess, and therefore leave it to the inquiry of posterity."

Various opinions and theories have been advanced by astron both ancient and modern; but none have been able to settle the beyond controversy. Cassini thought it might proceed from an merable multitude of little bodies revolving around the Sun, refle faint light, like that of the milky-way. Kepler ascribed its appe to the atmosphere which he supposed to surround the Sun. E these theories have been discarded as being untenable. Pro Olmstead supposes it to be a nebulous body, or thin, gaseous revolving around the Sun, causing the METEORIC SHOWERS that occurred for several years in the month of November, in conseq of the earth's near approach to it, in its annual course around the Herschel and Professor Nichol assert that the ZODIACAL Li a phenomenon precisely similar to that exhibited by the nebulous and if we were living upon some distant star, the Sun would a to us like a star surrounded by a faint light similar to that of a c seen at a short distance, in a foggy or thick atmosphere.

The present theory of the ZODIACAL LIGHT may be summed a few words—namely, that the matter of which the Sun and pla are composed was originally in a thin, gaseous state, and has condensed into solid bodies, which form the Sun and planets; tha Zodiacal Light is a portion of this matter, which has not as yet sided into the Sun. It is estimated to extend beyond the orb Mercury, and perhaps that of Venus; if so, they must pass thro it twice during each revolution around the Sun.

probably does not vary much from the truth.) We will now place observer at each place with accurate instruments, and on a particu night, at 12 o'clock, the observer at New York finds a particular exactly in his zenith, or over head; but the observer at Albany fi the same star two degrees to the south of his zenith,- hence it be seen that there are two degrees between the two places; and as distance, by measurement, was found to be 138 miles, the two degr between New York and Albany are equal to 138 miles, or o degree equals 694 miles. Now, if we multiply the number of grees in the whole circle or circumference of the earth (360) 69 miles, it will give 24,930 miles the whole circumference the earth.

eus, and Medusa's Head.-This constellation is directly enith, or over head. It contains two stars of the 2d magnitude. in the breast of PERSEUS is called Mirzak, or Algenib; the ALGOL, in Medusa's head: it is about 15° east of the zenith. r is remarkable on account of its changeableness. It changes irs from the 2d to the 4th magnitude. It remains in this condiminutes, when it begins to increase in brightness; and in 4 and 40 minutes appears again of the 2d magnitude: in which continues 61 hours, when it begins to diminish again. Dr. Herttributes its variableness to spots upon its surface like those of , and that it revolves upon its axis.

tory. PERSEUS was the son of Jupiter and DANE. He was no born than he was cast into the sea with his mother, and was on the coast of one of the islands of CYCLADES. Polydectes, g of the place, treated them with kindness, and placed them care of the Priests of Minerva's Temple. He promised to pree King with the head of Medusa, the only one of the Gorgons as subject to mortality. They were represented with serpents ing about their heads instead of hair; their bodies grew indissogether, and their very looks had the power of turning into stone se on whom they fixed their eyes. Being equipped by the gods, unted into the air, conducted by Minerva, and came upon the rs, who, with the watchful snakes, were asleep, and with one ut off her head. Perseus then made his way through the air, Hedusa's head yet bleeding, in his hand, and from the blood dropped from it as he flew, sprang all those innumerable serhat have ever since infested the sandy deserts of Lybia.] angulum, the Triangle.-This is a small constellation est from Medusa's Head, in the constellation PERSEUS. It may wn by three stars, which form a triangle. This constellation is nt origin.

es, the Ram.-This constellation lies to the southwest, about m the zenith, and may easily be distinguished by three bright the head of the RAM, and nearly in a right line. This constelwenty-two centuries ago occupied the first sign in the ecliptic; or time the constellations of the zodiac and the signs of the ecliptic onded to each other: but in consequence of the retrograde mothe equinoxes, 50" a year, the constellations of the zodiac and s of the ecliptic have been separated from each other, by the back of the signs in the ecliptic about 31 degrees: so that the tation Aries is now in the sign Taurus of the ecliptic; and TauGemini, and Gemini in Cancer; and so on. This constellation y received its name from the Chaldean Shepherds, who were in ays the best astronomers, from the fact that their occupation led - be on the watch during the 'night, to defend their flocks from ages of wild beasts. They observed that when the sun entered ision of the heavens the lambs were with their flocks, or that it e season for the increase of their flocks-hence the Ram was propriately made to represent the sign.

was intended to show that this was the season for the increase o ox species-hence the name Taurus, or Bull.

Gemini, the Twins.-This constellation is situated a little to south of east, and may be known by two stars of the 2d magnitude, in each head of the Twins-their names (a) Castor and (8) Po This sign was originally represented by two goats, and was prob intended to indicate the season for the multiplication of this anima well as to show that there were usually two at a birth.

Cancer, the Crab.-This constellation is next east of GE It contains stars only of the 4th magnitude. It was observed by Ancients, that the sun, when it enters Cancer, passes sideway a the tropic, without crossing it, which was fitly represented by a which moves sideways.

Orion. This constellation is southeast of Taurus, and is one o most conspicuous constellations in the heavens. It contains two of the first magnitude. (NOTE.-See description of Map No. 1.)

Canis Minor, the Little Dog.-This constellation is so east of Gemini. It contains one star of the first magnitude, Proc and one of the 3d, MIRZA, in the head of the Dog.

Canis Major, the Great Dog.-This constellation is situ to the southeast, and near the horizon. The principal star is Si the brightest star in the whole heavens. (NOTE.-See explanatio Map No. 1.)

Lepus, the Hare.-This constellation is south of ORION. It tains three stars of the 3d magnitude. It is situated west of the Gi DOG, which seems to be pursuing it from east to west, owing to motion of the earth on its axis. The hare is one of those ani which ORION delighted in hunting, and for this reason was made i constellation, and placed near him, among the stars.

Eridanus, the River Po.-This constellation occupies a space in the heavens directly south of TAURUS. It will be found cult to trace it, in all its windings. Its entire height is 130 deg It commences near the star Rigel, in the foot of Orion. ERIDAN the name of a celebrated river in Italy, now known by the name river Po.

Cetus, the Whale.-This constellation occupies the l space of any in the heavens, and is west of the RIVER PO. A whale is the chief monster of the ocean, so is it the largest cons tion in the heavens. It is considered to be the famous sea m sent by Neptune to devour ANDROMEDA, because her mother, C peia had boasted herself fairer than JUNO, or the sea nymphs-bu slain by PERSEUs, and placed among the stars, in honor of his deeds.

Monoceros, the Unicorn.-This constellation is east of and was made out of the unformed stars of the ancients, which lay tered over a large space between the two dogs Canis Major and Minor. The Monoceros is a species of Unicorn or RHINOCEROS about the size of a horse, with one horn growing out of the mid its forehead.

Columba, the Dove.-This constellation is south of the I THE HARE. It is so near the horizon that it probably will visible. It was introduced among the constellations by Roga in

Camelopardalus, the Giraffe.--This constellation was by HEVELIUS, in the beginning of the 17th century. It was m of stars not included in the adjacent constellations, viz : PERSEU RIGA, the head of URSA MAJOR, and the POLE Star.