side of the Herdsman is a circle consisting
of five stars of the third and fourth magnitude, save the third,
[alpha], or the Pearl, which is of the second magnitude. This is the
Corona Borealis. It is very easily recognized (Fig. 8).

[Illustration: FIG. 8.--To find Arcturus, the Herdsman, and the Northern
Crown.]

A line drawn from the Pole-Star to Arcturus forms the base of an
equilateral triangle, the apex of which, situated opposite the Great
Bear, is occupied by Vega, or [alpha] of the Lyre, a splendid diamond of
ideal purity scintillating through the ether. This magnificent star, of
first magnitude, is, with Arcturus, the most luminous in our Heavens. It
burns with a white light, in the proximity of the Milky Way, not far
from a constellation that is very easily recognized by the arrangement
of its principal stars in the form of a cross. It is named Cygnus, the
Bird, or the Swan (Fig. 9), and is easy to find by the Square of
Pegasus, and the Milky Way. This figure, the brilliancy of whose
constituents (of the third and fourth magnitudes) contrasts strongly
with the pallor of the Milky Way, includes at its extremity at the foot
of the Cross, a superb double star, [beta] or Albirio: [alpha] of Cygnus
is also called Deneb. The first star of which the distance was
calculated is in this constellation. This little orb of fifth magnitude,
which hangs 69,000,000,000,000 kilometers (42,000,000,000,000 miles)
above our Earth, is the nearest of all the stars to the skies of Europe.

[Illustration: FIG. 9.--The Swan, Vega, the Eagle.]

Not far off is the fine Eagle, which spreads its wings in the Milky Way,
and in which the star Altair, [alpha], of first magnitude, is situated
between its two satellites, [beta] and [gamma].

The Constellation of Hercules, toward which the motions of the Sun are
impelling us, with all the planets of its system, is near the Lyre. Its
principal stars can be recognized inside the triangle formed by the
Pole-Star, Arcturus, and Vega.

All the Constellations described above belong to the Northern
Hemisphere. Those nearest the pole are called circumpolar. They revolve
round the pole in twenty-four hours.

Having now learned the Northern Heavens, we must come back to the Sun,
which we have left behind us. The Earth revolves round him in a year,
and in consequence he seems to revolve round us, sweeping through a vast
circle of the celestial sphere. In each year, at the same period, he
passes t