Page:Popular Science Monthly Volume 47.djvu/535

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PLEASURES OF THE TELESCOPE.

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scope may perfectly separate them so far as the stellar disks are concerned. Then, too, I have observed in my own experience that a very faint and close double is more difficult than a brighter pair not more widely separated, usually on account of the defect of light, and this is true even when the components of the faint double are of equal magnitude.

Σ 470, otherwise known as 32 Eridani, is a superb object on account of the colors of its components, the larger star being a rich topaz and the smaller an ultramarine; while the difference in magnitude is not as great as in many of the colored doubles. The magnitudes are fifth and seventh, distance 6·7″, p. 348°. The star γ, of magnitude two and a half, has a tenth-magnitude companion, distant 51″, p. 238°. Σ 516, also called 39 Eridani, consists of two stars of magnitudes sixth and ninth, distance 6·4″, p. 150″; colors, yellow and blue. The supposed binary character of this star has not yet been established.

In ο² a we come upon an interesting triple star, two of whose components at any rate we can easily see. The largest component is of the fourth magnitude. At a distance of 82″, p. 105°, we find a tenth-magnitude companion. This companion is itself double, the magnitudes of its components being tenth and eleventh, distance 2·6″, p. 98°. Hall says of these stars that they "form a remarkable system." He has also observed a fourth star of the twelfth magnitude, distant 45″ from the largest star, p. 85°. This is apparently unconnected with the others, although it is only half as distant as the tenth-magnitude component is from the primary. Σ 590 is interesting because of the similarity of its two components in size, both being of about the seventh magnitude, distance 10″, p. 318°.

Finally, we turn to the nebula 826. This is planetary in form and inconspicuous, but Lassell has described it as presenting a most extraordinary appearance with his great reflector—a circular nebula lying upon another fainter and larger nebula of a similar shape, and having a star in its center. Yet it may possibly be an immensely distant star cluster instead of a nebula, since its spectrum does not appear to be gaseous.

Prof. O. C. Marsh regards the discovery of the Pithecanthropus erectus in Java as an event equal in interest to that of the Neanderthal skull, and believes that no one can doubt that still other intermediate forms will eventually be brought to light. Nearly twenty years ago he placed on record his belief that such missing links existed, and should be looked for in the caves of the later Tertiary of Africa. The first announcement, however, has come from the East, where large anthropoid apes still survive, and where their ancestors were doubtless entombed under circumstances favorable to early discovery. The tropical regions of both Asia and Africa still offer most inviting fields to ambitious explorers.