meridian transit of the
present day, determined to see if he could find the parallax of the
stars by observing the intervals at which a pair of stars in opposite
quarters of the heavens crossed his meridian at opposite seasons of the
year. When, as he thought, he had won success, he published his
observations and conclusions under the title of Copernicus Triumphans.
But alas! the keen criticism of his successors showed that what he
supposed to be a swing of the stars from season to season arose from a
minute variation in the rate of his clock, due to the different
temperatures to which it was exposed during the day and the night. The
measurement of the distance even of the nearest stars evaded
astronomical research until Bessel and Struve arose in the early part
of the present century.

On some aspects of the problem of the extent of the universe light is
being thrown even now. Evidence is gradually accumulating which points
to the probability that the successive orders of smaller and smaller
stars, which our continually increasing telescopic power brings into
view, are not situated at greater and greater distances, but that we
actually see the boundary of our universe. This indication lends a
peculiar interest to various questions growing out of the motions of
the stars. Quite possibly the problem of these motions will be the
great one of the future astronomer. Even now it suggests thoughts and
questions of the most far-reaching character.

I have seldom felt a more delicious sense of repose than when crossing
the ocean during the summer months I sought a place where I could lie
alone on the deck, look up at the constellations, with Lyra near the
zenith, and, while listening to the clank of the engine, try to
calculate the hundreds of millions of years which would be required by
our ship to reach the star a Lyrae, if she could continue her course in
that direction without ever stopping. It is a striking example of how
easily we may fail to realize our knowledge when I say that I have
thought many a time how deliciously one might pass those hundred
millions of years in a journey to the star a Lyrae, without its
occurring to me that we are actually making that very journey at a
speed compared with which the motion of a steamship is slow indeed.
Through every year, every hour, every minute, of human history from the
first appearance of man on the earth, from the era of the builders of
the Pyramids, through the times of