our celestial explorations with the little constellation Lyra,
whose chief star, Vega (alpha), has a very good claim to be regarded as
the most beautiful in the sky. The position of this remarkable star is
indicated in map No. 17. Every eye not insensitive to delicate shades of
color perceives at once that Vega is not white, but blue-white. When the
telescope is turned upon the star the color brightens splendidly.
Indeed, some glasses decidedly exaggerate the blueness of Vega, but the
effect is so beautiful that one can easily forgive the optical
imperfection which produces it. With our four-inch we look for the
well-known companion of Vega, a tenth-magnitude star, also of a blue
color deeper than the hue of its great neighbor. The distance is 50", p.
158 deg.. Under the most favorable circumstances it might be glimpsed with
the three-inch, but, upon the whole, I should regard it as too severe a
test for so small an aperture.

Vega is one of those stars which evidently are not only enormously
larger than the sun (one estimate makes the ratio in this case nine
hundred to one), but whose physical condition, as far as the
spectroscope reveals it, is very different from that of our ruling orb.
Like Sirius, Vega displays the lines of hydrogen most conspicuously, and
it is probably a much hotter as well as a much more voluminous body
than the sun.

Close by, toward the east, two fourth-magnitude stars form a little
triangle with Vega. Both are interesting objects for the telescope, and
the northern one, epsilon, has few rivals in this respect. Let us first
look at it with an opera glass. The slight magnifying power of such an
instrument divides the star into two twinkling points. They are about
two and a quarter minutes of arc apart, and exceptionally sharp-sighted
persons are able to see them divided with the naked eye. Now take the
three-inch telescope and look at them, with a moderate power. Each of
the two stars revealed by the opera glass appears double, and a fifth
star of the ninth magnitude is seen on one side of an imaginary line
joining the two pairs. The northern-most pair is named epsilon_1, the
magnitudes being fifth and sixth, distance 3", p. 15 deg.. The other pair is
epsilon_2, magnitudes fifth and sixth, distance 2.3", p. 133 deg.. Each pair
is apparently a binary; but the period of revolution is unknown. Some
have guessed a thousand years for one pair, and two thousand for the
other. Another guess gives ep