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ern of the three stars in the Belt of Orion, is exactly over the equator, so that from that star to the north pole star is exactly 90 degrees.

The Pleiades are in the Zodiac, on the south side; and so is the red star Aldeberan, near them; and the two bright stars about forty degrees to the left, called Castor and Pollux, or the Twins, are also in the Zodiac, and about five degrees north of the sun's place, on the 12th of July.

On such an evening, the Milky-way will be seen extending from north north-east to south south-west, as a light cloud; supposed by some to be formed of a mass or shoal of stars, almost infinite in number, but indistinct from their distance; though others suppose it to consist of a luminous space, and not of stars.

A celestial globe, rectified to the day and hour, will point to other objects; an ephemeris will indicate the names or places of the planets which may then be above the horizon; and any telescope will render visible many other interesting and wonderful phenomena.

Should the moon be visible, the motion in her orbit may be nightly traced by her approximating to, or receding from, certain stars; and the same may be observed in the motion of the planets in their orbits.

The morning and evening stars are the bright planets, Venus and Jupiter, so called from their rising or setting with the sun. Mars is red; Saturn of a leaden colour; Herschel is so distant, and Mercury is so near the sun, that they can seldom be seen but with a telescope.

VENUS, AS SEEN THROUGH A TELESCOPE.

[graphic]

Very small telescopes will shew most of the celestial phenomena; Jupiter's moons, Saturn's ring, the moonlike phases

of Venus, the Pleiades, the luminous space in the sword of Orion, the spots in the Sun, and the mountains in the Moon, may all be seen with such telescopes as are bought for fifteen or twenty shillings. Galileo made all his great discoveries with a telescope eight or ten inches long, and which magnified only ten or twelve times.

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267. The stars, according to their distances, are of seven sizes, called first magnitude, second magnitude, &c. down to the seventh magnitude, which can only be seen with a telescope. The stars may be distinguished from the planets by their twinkling; whereas the planets have a steady light.

Obs.-Having now acquired some knowledge of the won

ern of the three stars in the Belt of Orion, is exactly over the equator, so that from that star to the north pole star is exactly 90 degrees.

The Pleiades are in the Zodiac, on the south side; and so is the red star Aldeberan, near them; and the two bright stars about forty degrees to the left, called Castor and Pollux, or the Twins, are also in the Zodiac, and about five degrees north of the sun's place, on the 12th of July.

On such an evening, the Milky-way will be seen extending from north north-east to south south-west, as a light cloud; supposed by some to be formed of a mass or shoal of stars, almost infinite in number, but indistinct from their distance; though others suppose it to consist of a luminous space, and not of stars.

A celestial globe, rectified to the day and hour, will point to other objects; an ephemeris will indicate the names or places of the planets which may then be above the horizon; and any telescope will render visible many other interesting and wonderful phenomena.

Should the moon be visible, the motion in her orbit may be nightly traced by her approximating to, or receding from, certain stars; and the same may be observed in the motion of the planets in their orbits.

The morning and evening stars are the bright planets, Venus and Jupiter, so called from their rising or setting with the Mars is red; Saturn of a leaden colour; Herschel is so distant, and Mercury is so near the sun, that they can seldom be seen but with a telescope.

sun.

[merged small][graphic]

Very small telescopes will shew most of the celestial phenomena; Jupiter's moons, Saturn's ring, the moonlike phases

of Venus, the Pleiades, the luminous space in the sword of Orion, the spots in the Sun, and the mountains in the Moon, may all be seen with such telescopes as are bought for fifteen or twenty shillings. Galileo made all his great discoveries with a telescope eight or ten inches long, and which magnified only ten or twelve times.

[merged small][graphic][merged small]
[graphic]

267. The stars, according to their distances, are of seven sizes, called first magnitude, second magnitude, &c. down to the seventh magnitude, which can only be seen with a telescope. The stars may be distinguished from the planets by their twinkling; whereas the planets have a steady light.

Obs. Having now acquired some knowledge of the won

derful things around the EARTH, which surpass the conception or imagination of man, we will return again to it, observing, that these fixed stars and other celestial objects are constantly made use of to determine the relative situation of places; and that they are unerring guides both in regard to time and place.

268. Besides the motion round the sun in their respective years, the earth and the planets also turn round on their own axes and by turning to and from the sun, produce to their inhabitants, alternate light and darkness, or day and night; so that their seasons and years are produced by the grand revolution round the sun; and their days and nights by turning on their

own axes.

Obs. If a boy throw a ball out of his hand, besides going forwards, it turns round on its axis, and this is the precise motion of the earth and planets. So likewise the ball of a billiard table moves onward, and also turns on its axis.

269. The distances of the seven primary planets from the sun, in round millions, are- -Mercury 36, Venus 68, Earth 95, Mars 142, Jupiter 486, Saturn h 892, and Herschel H 1,800 millions miles from the sun.

Their diameters are respectively 3, 8, 8, 4, 89, 79, and 35 thousand miles.

And their periods of revolution are 3, 7, 12, 22, 144, 340, and 1000 months.

270. In their grand orbits, the planets do not move exactly in the same level or plane; but each moves regularly in its own level. Nor are their axes exactly perpendicular to the plane of their orbits, but variously inclined; and this inclination produces the difference of their seasons, and the different lengths of day and night.

271. The whole earth is calculated to be 4 times heavier than water; the Sun, Jupiter, and Herschel about the weight of water; Mercury nine times, and Venus six times heavier. In this way, taking matter

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