This technical description is far from the poetry of Nature; but it is especially important here to be clear and precise. Let us suppose ourselves, however, under the starry vault on a beautiful summer’s night, splendid and silent, and let us consider that each of these points which we seek to recognize is a world, or rather a system of worlds. Look at this equilateral triangle (Fig 10); it permits us to cast our eyes successively on three important suns: Vega of the Lyre, Arcturus of Boötes, and the pole star, which watches above the solitudes of our mysterious North Pole. Many martyrs of science have died looking at it! In twelve thousand years our descendants will see the Lyre at the pole, ruling the harmony of the heavens.
The stars which are near the pole, and which have for that reason received the name of circumpolar stars, are distributed in the groups which have just been indicated. I earnestly invite my readers to profit by fine evenings, and try to find for themselves these constellations in the sky.
We have here the principal stars and constellations of the Northern Hemisphere, the North Pole being at the centre of the circle. We come now in the order of our description to the twelve constellations of the zodiacal belt, which makes the circuit of the sky, inclined at 23° to the Equator, and of which the ecliptic, the apparent path of the sun, forms the centre line.
The name of zodiac, given to the zone of stars which the sun traverses during the course of the year, comes from ζώδια, animals, an etymology which is due to the species of figures traced on this belt of stars. Animals, in fact, predominate in these figures. The entire circumference of the sky has been divided into twelve parts, which have been named the twelve signs of the zodiac; our ancestors called them the “houses of the sun,” or “the monthly abodes of Apollo,” because the day star visits them each month, and returns every spring to the beginning of the zodiacal city. Two memorable Latin verses of the poet Ausonius present to us these twelve signs in the order in which the sun travels through them, and this still appears the easiest method of learning them by heart.
Sunt Aries, Taurus, Gemini, Cancer, Leo, Virgo,
Libraque, Scorpius, Arciteneus, Caper, Amphora, Pisces;
or, in English, the Ram ♈︎, the Bull ♉︎, the Twins ♊︎, the Crab ♋︎, the Lion ♌︎, the Virgin ♍︎, the Balance ♎︎, the Scorpion ♏︎, the Archer ♐︎, Capricornus ♑︎, Aquarius ♒︎, and the Fishes ♓︎. The signs placed beside these names are a vestige of the primitive hieroglyphics which described them: ♈︎ represents the horns of the Ram, ♉︎ the head of the Bull; ♒︎ is a stream of water, etc.
If we now know our northern sky, if its most important stars are sufficiently noted down in our mind, with the reciprocal relations which they preserve among themselves, we have no more confusion to fear, and it will be easy to recognize the zodiacal constellations. This zone may be of use to us as a line of division between the north and the south. Here is a description of it:
The Ram, which, moving in front of the herd, and regulating, so to say, the march, opens the series. This constellation has in itself nothing remarkable; the brightness of its stars indicates the base of one of the horns of the leader of the sheep; it is but of the second magnitude. After the Ram comes the Bull. Admire on a fine winter’s night the charming Pleiades which scintillate in the ether; not far from them shines a fine red star—this is the eye of the Bull—Aldebaran, a star of the first magnitude and one of the finest of our sky. We now arrive at the Twins, whose heads are marked by two fine stars of the second magnitude, situated a little above a star of the first magnitude—Procyon, or the Little Dog; Cancer, or the Crab, a constellation very little conspicuous (its most visible stars are but of the fourth magnitude, and occupy the body of the animal); the Lion, a fine constellation, marked by a star of the first magnitude, Regulus, by one of the second, β, and by several others of the second and third magnitudes arranged in a trapezium; the Virgin, indicated by a very brilliant star of the first magnitude; Spica, situated in the neighborhood of a star, also of the first magnitude, Arcturus, which is found on the prolongation of the tail of the Great Bear; the Balance (Libra), indicated by two stars of the second magnitude, which would exactly resemble the Twins if they were nearer to each other; the Scorpion, a remarkable constellation; a star of the first magnitude, of a fine red color, marks the Heart (Antares), in the middle of two stars of the third magnitude, above which are three bright stars arranged in a diadem; Sagittarius, the Archer, of which the arrow, indicated by three stars of the second and third magnitudes, is pointed toward the tail of the Scorpion; Capricornus, a constellation not conspicuous, which is recognized by two stars of the third magnitude very near each other, and representing the base of the horns of the hieroglyphic animal; Aquarius, indicated by three stars of the third magnitude arranged in a triangle, of which the most northern occupies a point on the equator; Pisces, the Fishes, composed of stars, barely conspicuous, of the third to fourth magnitudes, situated to the south of a large and magnificent quadrilateral—the Square of Pegasus—of which we have already spoken.