a half, distance 1.8", p. 42 deg.. But (and
this was another of Burnham's discoveries) the fourth-magnitude star
itself is double, distance 0.8", p. about 0 deg.. The companion in this case
is of magnitude five and a half.

Next we shall need a rather low-power eyepiece and our largest aperture
in order to examine a star cluster, No. 4173, which was especially
admired by Sir William Herschel, who discovered that it was not, as
Messier had supposed, a circular nebula. Herschel regarded it as the
richest mass of stars in the firmament, but with a small telescope it
appears merely as a filmy speck that has sometimes been mistaken for a
comet. In 1860 a new star, between the sixth and seventh magnitude in
brilliance, suddenly appeared directly in or upon the cluster, and the
feeble radiance of the latter was almost extinguished by the superior
light of the stranger. The latter disappeared in less than a month, and
has not been seen again, although it is suspected to be a variable, and,
as such, has been designated with the letter T. Two other known
variables, both very faint, exist in the immediate neighborhood.
According to the opinion that was formerly looked upon with favor, the
variable T, if it is a variable, simply lies in the line of sight
between the earth and the star cluster, and has no actual connection
with the latter. But this opinion may not, after all, be correct, for
Mr. Bailey's observations show that variable stars sometimes exist in
large numbers in clusters, although the variables thus observed are of
short period. The cluster 4183, just west of Antares, is also worth a
glance with the five-inch glass. It is dense, but its stars are very
small, so that to enjoy its beauty we should have to employ a large
telescope. Yet there is a certain attraction in these far-away glimpses
of starry swarms, for they give us some perception of the awful
profundity of space. When the mind is rightly attuned for these
revelations of the telescope, there are no words that can express its
impressions of the overwhelming perspective of the universe.

The southern part of the constellation Ophiuchus is almost inextricably
mingled with Scorpio. We shall, therefore, look next at its attractions,
beginning with the remarkable array of star clusters 4264, 4268, 4269,
and 4270. All of these are small, 2' or 3' in diameter, and globular in
shape. No. 4264 is the largest, and we can see some of the stars
composing it. But these cl