Fornax, the Furnace, lies south of Cetus, west of Eridanus, and east of Sculptor and Phœnix. It was formed by Lacaille, and is supposed to represent a chemical furnace with an alembic and receiver! Its brightest star, α Fornacis, is identical with 12 Eridani.
Cælum, the Sculptor’s Tools, is a small constellation east of Columba, and west of Eridanus. It was formed by Lacaille. The brightest stars are α and γ, which are about 4½ magnitude. α has a faint companion; and γ is a wide double star to the naked eye.
Antlia, the Air Pump, lies south of Hydra, east and north of Argo, and west of Centaurus. It was formed by Lacaille. It contains no star brighter than 4th magnitude. The brightest, α, has been variously rated from 4 to 5, and Stanley Williams thinks its variability “highly probable.”
Norma, the Rule, lies south of Scorpio. It contains no star brighter than the 4th magnitude.
Telescopium.—This modern constellation lies south of Corona Australis, and north of Pavo. Its stars α, δ, and ζ, which lie near the northern boundary of the constellation, are referred to by Al-Sufi in his description of Ara.
Microscopium.—This small constellation is south of Capricornus, and west of Piscis Australis. Its stars seem to be referred to by Al-Sufi as having been seen by Ptolemy, but he does not specify their exact positions. It contains no star brighter than 4½ magnitude.
South of Al-Sufi’s horizon are a number of constellations surrounding the south pole, which, of course, he could not see. Most of these have been formed since his time, and these will now be considered; beginning with that immediately surrounding the South Pole (Octans), and then following the others as nearly as possible in order of Right Ascension.
Octans.—This is the constellation surrounding the South Pole of the heavens. There is no bright star near the Pole, the nearest visible to the naked eye being σ Octantis, which is within one degree of the pole. It was estimated 5·8 at Cordoba. The brightest star in the constellation is ν Octantis (α, Proctor), which lies about 12 degrees from the pole in the direction of Indus and Microscopium. The Harvard measure is 3·74 magnitude.
Hydrus, the Water-Snake, is north of Octans in the direction of Achernar (α Eridani). The brightest star is β, which lies close to θ Octantis. The Harvard measure is 2·90. Gould says its colour is “clear yellow.” It has a large proper motion of 2″·28 per annum. Sir David Gill found a parallax of 0″·134, and this combined with the proper motion gives a velocity of 50 miles a second at right angles to the line of sight. γ Hydri is a comparatively bright star of about the 3rd magnitude, about 15½ degrees from the South Pole. It is reddish, with a spectrum of the third type.