In the eighteenth century the French astronomer Lacaille, who did much excellent work in the southern hemisphere with a tiny telescope of only half an inch aperture, had the unhappy idea of filling up the spaces still left empty with scientific instruments. It is easy to make Birds of Paradise and Flying Fishes out of the stars, but such things as telescopes, easels, and sextants do not lend themselves to irregular groups, and they are very much out of place among the mythical beasts and heroes which we are accustomed to see on our star-maps. Fortunately the beginner need not learn to recognise these intruders, for there are no bright stars in them, although there are many interesting objects for telescopic study. We need only note that Octans, the Octant, occupies the region in which the south pole is situated, which is quite bare of bright stars. The pole itself may be found by drawing a line from head to foot of the Cross and carrying it on about four times as far again; or if the Cross is invisible, the pole may be found near the middle of a line from Canopus to Alpha Pavonis.
II
THE CONSTELLATIONS OF THE SOUTH:
ANCIENT GROUPS
Let us turn once more to the Southern Cross to find the ancient constellations. It is both ancient and modern itself, for its stars were known to the Greeks of Alexandria, but were included in the Centaur. The latter, like all those shown in the accompanying illustration, is of great antiquity, and probably of Babylonian origin. The two stars which we call the Pointers to the Cross are Alpha and Beta of the Centaur, and mark his forefeet. Another conspicuous pair, Delta and Gamma, are on his horse’s body, while his man’s shoulders are marked by many bright stars, and the head is formed by a little group. His arm stretches out through bright Eta to Kappa, which is very close to Beta Lupi. For the Centaur and Lupus form one large and very brilliant group, and were perhaps connected with the little constellation of Ara, the Altar, upon which the Centaur seems to have been imagined as offering the creature which we now know as the Wolf, though its older name was simply the Beast. Aratus, a Greek poet of about 300 b.c., to whom we owe the earliest description extant of the ancient constellations, says of the Centaur:
“His right hand he ever seems to stretch
Before the Altar’s circle. The hand grasps
Another creature, very firmly clutched,
The Wild Beast,—so the men of old it named.”
The Old Constellation Figures
of the Southern Hemisphere.
On the other side of the Cross is another splendid constellation, the Ship Argo, which covers a large space of the sky with many bright stars, among them Canopus, the brightest in the whole heavens except Sirius. For convenience this large constellation has been divided into four—the Keel, the Poop, the Mast, and the Sails.