Vega. In the
great Harvard refractor Vega is seen with no less than thirty-five
companions. I imagine that all these stars, and others which can be seen
in neighbouring fields, indicate the association of Vega with the
neighbouring stream of the Milky Way.

Let our observer now direct his telescope to the star [epsilon] Lyrae. Or
rather, let him first closely examine this star with the naked eye. The
star is easily identified, since it lies to the left of Vega, forming
with [zeta] a small equilateral triangle. A careful scrutiny suffices to
indicate a peculiarity in this star. If our observer possesses very
good eye-sight, he will distinctly recognise it as a "naked-eye double";
but more probably he will only notice that it appears lengthened in a
north and south direction.[4] In the finder the star is easily divided.
Applying a low power to the telescope itself, we see [epsilon] Lyrae as a
wide double, the line joining the components lying nearly north and
south. The southernmost component (the upper in the figure) is called
[epsilon]^{1}, the other [epsilon]^{2}. Seen as a double, both
components appear white.

Now, if the observer's telescope is sufficiently powerful, each of the
components may be seen to be itself double. First try [epsilon]^{1}, the
northern pair. The line joining the components is directed as shown in
Plate 3. The distance between them is 3".2, their magnitudes 5 and
6-1/2, and their colours yellow and ruddy. If the observer succeeds in
seeing [epsilon]^{1} fairly divided, he will probably not fail in
detecting the duplicity of [epsilon]^{2}, though this is a rather closer
pair, the distance between the components being only 2".6. The
magnitudes are 5 and 5-1/2, both being white. Between [epsilon]^{1} and
[epsilon]^{2} are three faint stars, possibly forming with the quadruple
a single system.

Let us next turn to the third star of the equilateral triangle mentioned
above--viz. to the star [zeta] Lyrae. This is a splendid but easy double.
It is figured in Plate 3, but it must be noticed that the figure of
[zeta] and the other nine small figures are not drawn on the same scale
as [epsilon] Lyrae. The actual distance between the components of [zeta]
Lyra is 44", or about one-fourth of the distance separating
[epsilon]^{1} from [epsilon]^{2}. The components of [zeta] are very
nearly equal in magnitude, in colour topaz and green, the topaz
component being estimated as of the fifth magnitude, the g