the heavens are at distances so much
greater than that of Neptune that our solar system is like a little
colony, separated from the rest of the universe by an ocean of void
space almost immeasurable in extent. The orbit of the earth round the
sun is of such size that a railway train running sixty miles an hour,
with never a stop, would take about three hundred and fifty years to
cross it. Represent this orbit by a lady's finger-ring. Then the
nearest fixed star will be about a mile and a half away; the next more
than two miles; a few more from three to twenty miles; the great body
at scores or hundreds of miles. Imagine the stars thus scattered from
the Atlantic to the Mississippi, and keep this little finger-ring in
mind as the orbit of the earth, and one may have some idea of the
extent of the universe.

One of the most beautiful stars in the heavens, and one that can be
seen most of the year, is a Lyrae, or Alpha of the Lyre, known also as
Vega. In a spring evening it may be seen in the northeast, in the later
summer near the zenith, in the autumn in the northwest. On the scale we
have laid down with the earth's orbit as a finger-ring, its distance
would be some eight or ten miles. The small stars around it in the same
constellation are probably ten, twenty, or fifty times as far.

Now, the greatest fact which modern science has brought to light is
that our whole solar system, including the sun, with all its planets,
is on a journey towards the constellation Lyra. During our whole lives,
in all probability during the whole of human history, we have been
flying unceasingly towards this beautiful constellation with a speed to
which no motion on earth can compare. The speed has recently been
determined with a fair degree of certainty, though not with entire
exactness; it is about ten miles a second, and therefore not far from
three hundred millions of miles a year. But whatever it may be, it is
unceasing and unchanging; for us mortals eternal. We are nearer the
constellation by five or six hundred miles every minute we live; we are
nearer to it now than we were ten years ago by thousands of millions of
miles, and every future generation of our race will be nearer than its
predecessor by thousands of millions of miles.

When, where, and how, if ever, did this journey begin--when, where, and
how, if ever, will it end? This is the greatest of the unsolved
problems of astronomy. An astronomer who should watch the heavens