silon_1 a period of one thousand years, and
epsilon_2 a period of eight hundred years. Hall, in his double-star
observations, simply says of each, "A slow motion."

Purely by guesswork a period has also been assigned to the two pairs in
a supposed revolution around their common center, the time named being
about a million years. It is not known, however, that such a motion
exists. Manifestly it could not be ascertained within the brief period
during which scientific observations of these stars have been made. The
importance of the element of time in the study of stellar motions is
frequently overlooked, though not, of course, by those who are engaged
in such work. The sun, for instance, and many of the stars are known
to be moving in what appear to be straight lines in space, but
observations extending over thousands of years would probably show that
these motions are in curved paths, and perhaps in closed orbits.

If now in turn we take our four-inch glass, we shall see something else
in this strange family group of epsilon Lyrae. Between epsilon_1 and
epsilon_2, and placed one on each side of the joining line, appear two
exceedingly faint specks of light, which Sir John Herschel made famous
under the name of the _debillissima_. They are of the twelfth or
thirteenth magnitude, and possibly variable to a slight degree. If you
can not see them at first, turn your eye toward one side of the field of
view, and thus, by bringing their images upon a more sensitive part of
the retina, you may glimpse them. The sight is not much, yet it will
repay you, as every glance into the depths of the universe does.

The other fourth-magnitude star near Vega is zeta, a wide double,
magnitudes fourth and sixth, distance 44", p. 150 deg.. Below we find beta,
another very interesting star, since it is both a multiple and an
eccentric variable. It has four companions, three of which we can easily
see with our three-inch; the fourth calls for the five-inch; the
magnitudes are respectively four, seven or under, eight, eight and a
half, and eleven; distances 45", p. 150 deg.; 65", p. 320 deg.; 85", p. 20 deg.; and
46", p. 248 deg.. The primary, beta, varies from about magnitude three and a
half to magnitude four and a half, the period being twelve days,
twenty-one hours, forty-six minutes, and fifty-eight seconds. Two
unequal maxima and minima occur within this period. In the spectrum of
this star some of the hydrogen lines and the D_3 line (t