In looking back over a century’s work in the oldest of the sciences,
one is struck not only by the enormous advance that has been made in
those branches of the science dealing with the motions of the heavenly
bodies which were cultivated at least eight thousand years ago by
early dwellers in the valleys of the Nile, Tigris, and Euphrates,
but with the fact that during the century that has just passed away
a perfectly new science of astronomy arose. By annexing physics and
chemistry astronomers now study the motions of the particles of which
all celestial bodies are composed; a new molecular astronomy has now
been firmly established side by side with the old molar astronomy which
formerly alone occupied the thoughts of star-gazers.
Along this new line our knowledge has advanced by leaps and bounds, and
the results already obtained in expanding and perfecting man’s views of
nature in all her beauty and immensity are second to none which have
been garnered during the last hundred years.