Astronomy,--which of all sciences has filled men's minds with general
ideas of a character most foreign to their daily experience, and has,
more than any other, rendered it impossible for them to accept the
beliefs of their fathers. Astronomy,--which tells them that this so vast
and seemingly solid earth is but an atom among atoms, whirling, no man
knows whither, through illimitable space; which demonstrates that what
we call the peaceful heaven above us, is but that space, filled by an
infinitely subtle matter whose particles are seething and surging, like
the waves of an angry sea; which opens up to us infinite regions where
nothing is known, or ever seems to have been known, but matter and
force, operating according to rigid rules; which leads us to contemplate
phenomena the very nature of which demonstrates that they must have had
a beginning, and that they must have an end, but the very nature of
which also proves that the beginning was, to our conceptions of time,
infinitely remote, and that the end is as immeasurably distant.

But it is not alone those who pursue astronomy who ask for bread and
receive ideas. What more harmless than the attempt to lift and
distribute water by pumping it; what more absolutely and grossly
utilitarian? But out of pumps grew the discussions about Nature's
abhorrence of a vacuum; and then it was discovered that Nature does not
abhor a vacuum, but that air has weight; and that notion paved the way
for the doctrine that all matter has weight, and that the force which
produces weight is co-extensive with the universe,--in short, to the
theory of universal gravitation and endless force. While learning how to
handle gases led to the discovery of oxygen, and to modern chemistry,
and to the notion of the indestructibility of matter.

Again, what simpler, or more absolutely practical, than the attempt to
keep the axle of a wheel from heating when the wheel turns round very