iries.

The establishment of the new method of spectrum analysis drew far closer
this alliance between celestial and terrestrial science. Indeed, they
have come to merge so intimately one into the other, that it is no
easier to trace their respective boundaries than it is to draw a clear
dividing-line between the animal and vegetable kingdoms. Yet up to the
middle of the last century, astronomy, while maintaining her strict
union with mathematics, looked with indifference on the rest of the
sciences; it was enough that she possessed the telescope and the
calculus. Now the materials for her inductions are supplied by the
chemist, the electrician, the inquirer into the most recondite mysteries
of light and the molecular constitution of matter. She is concerned with
what the geologist, the meteorologist, even the biologist, has to say;
she can afford to close her ears to no new truth of the physical order.
Her position of lofty isolation has been exchanged for one of community
and mutual aid. The astronomer has become, in the highest sense of the
term, a physicist; while the physicist is bound to be something of an
astronomer.

This, then, is what is designed to be conveyed by the "foundation of
astronomical or cosmical physics." It means the establishment of a
science of Nature whose conclusions are not only presumed by analogy,
but are ascertained by observation, to be valid wherever light can
travel and gravity is obeyed--a science by which the nature of the stars
can be studied upon the earth, and the nature of the earth can be made
better known by study of the stars--a science, in a word, which is, or
aims at being, one and universal, even as Nature--the visible reflection
of the invisible highest Unity--is one and universal.

It is not too much to say that a new birth of knowledge has ensued. The
astronomy so signally promoted by Bessel[403]--the astronomy placed by
Comte[404] at the head of the hierarchy of the physical sciences--was
the science of the _movements_ of the heavenly bodies. And there were
those who began to regard it as a science which, from its very
perfection, had ceased to be interesting--whose tale of discoveries was
told, and whose farther advance must be in the line of minute technical
improvements, not of novel and stirring disclosures. But the science of
the _nature_ of the heavenly bodies is one only in the beginning of its
career. It is full of the audacities, the inconsistencies, the
impe