ula. We may also glance at another nebula, 4678, which appears
circular and is pinned with a little star at the edge.

The small constellation Equuleus contains a surprisingly large number of
interesting objects. Sigma 2735 is a rather close double, magnitudes six
and eight, distance 1.8", p. 287 deg.. Sigma 2737 (the first star to the
left of Sigma 2735, the name having accidentally been omitted from the
map) is a beautiful triple, although the two closest stars, of
magnitudes six and seven, can not be separated by our instruments. Their
distance in 1886 was 0.78", p. 286 deg., and they had then been closing
rapidly since 1884, when the distance was 1.26". The third star, of
magnitude eight, is distant 11", p. 75 deg.. Sigma 2744 consists of two
stars, magnitudes six and seven, distance 1.4", p. 1.67 deg.. It is probably
a binary. Sigma 2742 is wider double, magnitudes both six, distance
2.6", p. 225 deg.. Another triple, one of whose components is beyond our
reach, is gamma. Here the magnitudes are fifth, twelfth, and sixth,
distances 2", p. 274 deg. and 366". It would also be useless for us to try
to separate delta, but it is interesting to remember that this is one of
the closest of known double stars, the magnitudes being fourth and
fifth, distance 0.4", p. 198 deg.. These data are from Hall's measurements
in 1887. The star is, no doubt, a binary. With the five-inch we may
detect one and perhaps two of the companion stars in the quadruple beta.
The magnitudes are five, ten, and two eleven, distances 67", p. 309 deg.;
86", p. 276 deg.; and 6.5", p. 15 deg.. The close pair is comprised in the
tenth-magnitude star.

[Illustration: MAP NO. 19.]

Map No. 19 introduces us to the constellation Pegasus, which is
comparatively barren to the naked eye, and by no means rich in
telescopic phenomena. The star epsilon, of magnitude two and a half, has
a blue companion of the eighth magnitude, distance 138", p. 324 deg.; colors
yellow and violet. A curious experiment that may be tried with this star
is described by Webb, who ascribes the discovery of the phenomenon to
Sir John Herschel. When near the meridian the small star in epsilon
appears, in the telescope, underneath the large one. If now the tube of
the telescope be slightly swung from side to side the small star will
appear to describe a pendulumlike movement with respect to the large
one. The explanation suggested is that the comparative faintness of the
small star caus