[4] Right ascension in the skies corresponds with longitude on earth, but is more often reckoned in time than in degrees. For instance, R.A. 1 hour 35 minutes, the right ascension of Achernar, means that this star will be on the meridian 1 hour 35 minutes later than the “first point of Aries”—that is, the point at which the equator cuts the ecliptic at the spring equinox, the fundamental point corresponding with Greenwich in earthly longitude. There are more bright stars in the southern hemisphere than in the north, for a count of all those above fourth magnitude shows that there are 228 south of the equator against only 164 north. But whereas the stars in the north are fairly evenly distributed, there is a more strongly marked tendency in the south to congregate on the Milky Way, so that, while the tract through Argo and the Cross to Scorpio and Sagittarius is extraordinarily rich, the part between Orion and Fomalhaut is comparatively dark and bare, and the regions round the south pole and north of Argo are also very barren of bright stars. Some regions, however, which look dull to the eye abound in marvels for the telescope and camera. The brilliance and the complex structure of the Milky Way is undoubtedly what most strikes the northerner travelling south. In England we have a glimpse of it in Cygnus and Aquila, where this rich and bright part begins; but there is nothing to equal the brightness or the mingling of dark and light which we see in Argo and near the Cross, in Scorpio and in Sagittarius. When this part is about to rise, there is often a glow on the horizon as if it were dawn. III THE TEN BRIGHTEST STARS OF THE SOUTHERN HEMISPHERE The brighter of the two Pointers to the Cross, Alpha Centauri, ranks very high among first-magnitude stars, though it is excelled in brightness by Sirius and Canopus; but its greatest claim to our interest is that among all the host of stars it is our nearest neighbour. Yet, should we decide to pay a visit and travel with the speed of light (11 million miles a minute), it would be four years and three months before we could reach our destination—so great are the spaces which separate our sun with his family of planets from the nearest of his brother suns. Alpha Centauri is also interesting as a double star. The two components are nearly equal in brightness, and are seen as a brilliant yellow pair in quite a small telescope. It was one of the first doubles known, being discovered as such in 1689; and Herschel calls it a “superb double star, beyond all comparison the most striking object of the kind in the heavens.” The two stars he describes as “both of a high ruddy or orange colour, though that of the smaller is of a somewhat more sombre and brownish cast.”