But we forget the stars. If our descriptions have been carefully followed, the reader will now know the zodiacal constellations as well as those of the north. There remains but little to do to know the entire sky. But there is an indispensable addition to be made to what precedes. The circumpolar stars are perpetually visible above the London horizon; at any time of the year when we wish to observe them it is sufficient to turn to the north, and we shall always find them, either above the pole star or below it, to one side or the other, and always maintaining among themselves the relations which we have employed to find them. The stars of the zodiac do not resemble them from this point of view, for they are sometimes above the horizon, sometimes below. It is necessary, then, to know at what epoch they are visible. For this purpose it will be sufficient to remember the constellation which is found in the middle of the sky at nine o’clock in the evening on the first day of each month—that, for example, which crosses at that moment a line descending from the zenith to the south. This line is the meridian, of which we have already spoken; all the stars cross it once a day, moving from east to west—that is to say, from left to right. In indicating each of the constellations which pass at the hour indicated, we also give the centre of the visible constellations.
On January 1 Taurus passes the meridian at 9 o’clock in the evening; notice Aldebaran, the Pleiades. On February 1 the Twins (Gemini) are not yet there; we see them a little to the left. March 1, Castor and Pollux have passed; Procyon to the south, the little stars of the Crab (Cancer) to the left. April 1, the Lion, Regulus. May 1, β of the Lion, Berenice’s Hair. June 1, Spica of the Virgin, Arcturus. July 1, the Balance (Libra), the Scorpion. August 1, Antares, Ophiuchus. September 1, Sagittarius, Aquila. October 1, Capricornus, Aquarius. November 1, Pisces, Pegasus. December 1, Aries, the Ram.
Our general review of the starry sky must now be completed by the stars of the southern heavens.
Below Taurus and Gemini, to the south of the zodiac, you notice the giant Orion, who raises his club toward the forehead of the Bull. Seven brilliant stars are here distinguished; two of them, α and β, are of the first magnitude; the five others are of the second magnitude, α and γ mark the shoulders, κ the right knee, β the left knee; δ, ε, ζ mark the belt or girdle. Below this line is a luminous train of three stars, very near each other; this is the Sword. Between the western shoulder and Taurus is seen the Shield, composed of a row of small stars. The head is marked by a little star (λ) of the fourth magnitude.
On a fine winter’s night turn toward the south, and you will immediately recognize this giant constellation. The four stars, α, γ, β, κ, occupy the angles of a great quadrilateral. The three others, δ, ε, ζ, are crowded in an oblique line in the middle of this quadrilateral; α, at the northeast angle, is named Betelgeuse (not Beteigeuse, as some books print it); β, at the southeast angle, is called Rigel.
The line of the Belt, produced both ways, passes to the northeast near Aldebaran, the Eye of the Bull, which we know already, and to the southeast near Sirius, the finest star of the sky, which we shall soon consider.
It is during the fine nights of winter that this constellation shines in the evening above our heads. No other season is so magnificently constellated as the months of winter. While nature deprives us of certain enjoyments in one way, it offers us in exchange others no less precious. The marvels of the heavens present themselves from Taurus and Orion in the east to Virgo and Boötes on the west. Of eighteen stars of the first magnitude which are counted in the whole extent of the firmament, a dozen are visible from nine o’clock to midnight, not to mention some fine stars of the second magnitude, remarkable nebulæ, and celestial objects well worthy of the attention of mortals. It is thus that nature establishes a harmonious compensation, and while it darkens our short and frosty days of winter, it gives us long nights enriched with the most opulent creations of the sky.
The constellation of Orion is not only the richest in brilliant stars, but it conceals for the initiated treasures which no other is known to afford. We might almost call it the California of the sky.
To the southeast of Orion, on the line of the Three Kings, shines the most magnificent of all the stars, Sirius, or α of the constellation of the Great Dog. This star of the first magnitude marks the upper eastern angle of a great quadrilateral, of which the base near the horizon of London, is adjacent to a triangle. This constellation rises in the evening at the end of November, passes the meridian at midnight at the end of January, and sets at the end of March. It played the greatest part in Egyptian astronomy, for it regulated the ancient calendar. It was the famous Dog Star; it predicted the inundation of the Nile, the summer solstice, great heats and fevers; but the precession of the equinoxes has in 3,000 years moved back the time of its appearance by a month and a half, and now this fine star announces nothing, either to the Egyptians who are dead or to their successors.