small ones, called the Hyades, forms a triangle. Between this triangle and Musca, is that well known cluster of stars, the Pleiades, or seven stars, situated in the neck of Taurus. A line from Aldebaran through Algol, will intersect Schedar, a star of the third magnitude in the constellation Cassiopeia. This constellation will easily be known, being composed of five or six stars of nearly the same magnitude, and being always on the opposite side of the pole, with respect to the star Alioth in Ursa Major.

16. About 22 degrees south-east from Aldeba ran, are three stars of the second magnitude in a straight line, which form the belt of Orion. Below the belt are a few stars that compose the sword of Orion, in a beautiful nebulæ. Above these are two bright stars, distant from each other about 7 degrees; the farthest west one is Bellatrix, and the other Betelgueze; and about as far dis. tant on the other side of the belt is Rigel, a star of the first magnitude; all of them are in Orion, one of the most beautiful constellations in the heavens.

17. About half way from Rigel and the north pole is Capella, a star of the first magnitude in the constellation Auriga. In a line from Menkar through Rigel, at the distance of 23 degrees from the latter, is Sirius, the brightest star in the heavens, in the mouth of Canis Major. A line from Aldebaran, through the middle of Orion's belt, and about as far below it as Aldebaran is above it, will also point out this remarkable star. About 5 degrees west from Sirius is a star between the second and third magnitudes, and about eleven degrees farther south than Sirius there are three others in a straight line, all of the third magni

tude, and in the same constellation. About 26 degrees to the east of Betelgueze, and the same distance north-east from Sirius, is Procyon, a star of the first magnitude, in the back of Canis Minor.

18. In a line with Rigel and the middle star in the belt of Orion, about 44 degrees from the latter, is Castor, a star of the first magnitude in the constellation Gemini, and about 4 degrees south-east of Castor is Pollux, a star of the second magnitude in the same constellation. Pollux may also be known by observing, that it is about 45 degrees distant from Aldebaran in the line produced, passing through it from Menkar.

19. About half way between Procyon and Regulus is Acubene, a star of the fourth magnitude, in Cancer.

20. A line from Alioth through Regulus being produced about 23 degrees, will intersect Alphared, a star of the second magnitude in the constellation Hydra; and a line from Procyon through Alphared, produced about 24 degrees beyond Alphared, will intersect Alkes in the Cup. This constellation may also be known by being on the meridian nearly at the same time with the pointers in the Great Bear,

21. Directly south of Arcturus, and about 80 degrees distant, is a, a star of the first magnitude, in the Centaur; and about 5 degrees nearly east of a, is ẞ, a star of the first magnitude in the same constellation. About 12 degrees nearly east from ẞ in the Centaur, is a in the Cross, a star of the first magnitude, and one of the most remarkable in all the southern constellations. A line passing through 7, a star of the first magnitude in the Cross, and a in the same constellation, will point out the south pole, about 28 degrees distant from the latter star, As the constellations and stars now described comprise the greater number of those that can be seen, in any part of the United States, it is unnecessary to take any notice of the others. Those who are possessed of a celestial globe, will in a few evenings, acquire a knowledge of the principal.stars that may be above the horizon at that season; but the foregoing directions will be found to answer the same purpose, without the assistance either of a globe or a map of the heavens. The use of the celestial globe in the solution of problems, relative to the stars, &c. shall be fully illustrated in the next chapter.

22. The Milky Way can be traced among the constellations, from Argo Navis, between Canis Major and Monoceros, then separating Taurus and Gemini, afterwards passing through Auriga, Perseus, Cassiopeia, Cepheus, Cygnus, Taurus Poniotowski, Scutum Sobieski, Sagittarius, Ara, Crux, and Roper Caroli, then revisiting Argo Navis.

The breadth of the Milky Way appears to be very unequal. In a few places it does not exceed five degrees, but, in several constellations, it is extended from ten to sixteen. In its course it runs nearly 12 degrees in a divided clustering stream, of which the two branches between Serpentarius and Antinous are expanded over more than 22 degrees. That the sun is within its plane, may be seen by an observer in the latitude of about 60 degrees; for, when at 100 degrees of right ascension, the Milky Way is in the east; it will at the same time be in the west at 180 degrees; while, in its meri dional situation, it will pass through Cassiopeia in the zenith, and through the constellation of the Cross in the nadir.

QUESTIONS.

By means of what constellation do you describe the position of the constellations and principal stars in the heavens?

Which is the most conspicuous constellation in the northern hemisphere?

How do you point out Alruccabah, or the north pole star?

How do you point out Cor Caroli, in the neck of Chara?

How do you point out Vindemiatrix ?

How do you point out Denebola in the Lion's

tail, and Regulus in his heart?

How do you point out Arcturus in Bootes, and

Spica Virginis in the hand of Virgo?

How do you point out Alphacca in the Northern Crown?

How do you point out Algorab in the Crow, and Antares in the heart of the Scorpion?

How do you point out Vega or Lyra in the Harp, Rastaben in the Dragon, and. Altair in the Eagle?

Name the figure which is formed by Altair, Lyra, and Deneb in the Swan.

How do you point out the rhomboidal figure in the Dolphin, Scheat in Pegasus, and the star in the head of Andromeda?

How do you point out Fomalhaut, in the Southern Fish? How do you point out Menkar in Cetus, and Algol in Perseus?

How do you point out Almaach in the foot of Andromeda ?

Describe the figure that is formed by Almaach, Algol, and Algenib.

Where is a Arietis situated, and how many degrees from Mirach?

How do you point out Aldebaran?

How do you point out Schedar in Cassiopeia? How do you point out the principal stars in Orion?

How do you point out Sirius, the brightest star in the heavens ?

How do you point out Procyon in Canis Minor ? How do you point out Castor and Pollux, both in Gemini?

How do you point out Alphared in the Hydra, and Alkes in the Cup?

How do you point out the principal stars in the

Centaur?

How do you trace the Milky Way among the constellations ?

CHAPTER VII.

Astronomical problems performed by the celestial globe.

PROBLEM I.

To find the right ascension and declination of the sun, or any fixed star.

RULE. Bring the sun's place in the ecliptic, or the star, to that part of the brazen meridian which is numbered from the equinoctial towards the poles; then the degree that is over the sun's place, or the star, is the declination; and the degree of the equinoctial cut by the meridian, reckoning from the vernal equinoctial point (or the sign r) eastward, is the right ascension.

Whenever the sun's place, or any fixed star, is brought to the brazen meridian, the graduated edge, which is numbered from the equinoctial towards the poles, is always to be understood, unless the contrary be expressed.

Or: Place both the poles in the horizon, bring the sun's place, or the star, to the eastern part of the horizon, then the degree cut on the horizon, counting from the east, northward or southward,