ery dissimilar; no person showed
himself more skilful in deducing important conclusions from those
unexpected affinities.

Towards the close of his days, for example, he overthrew with a stroke
of the pen, by the aid of certain observations of the moon, the
cosmogonic theories of Buffon and Bailly, which were so long in favour.

According to these theories, the earth was inevitably advancing to a
state of congelation which was close at hand. Laplace, who never
contented himself with a vague statement, sought to determine in numbers
the rapid cooling of our globe which Buffon had so eloquently but so
gratuitously announced. Nothing could be more simple, better connected,
or more demonstrative, than the chain of deductions of the celebrated
geometer.

A body diminishes in volume when it cools. According to the most
elementary principles of mechanics, a rotating body which contracts in
dimensions ought inevitably to turn upon its axis with greater and
greater rapidity. The length of the day has been determined in all ages
by the time of the earth's rotation; if the earth is cooling, the length
of the day must be continually shortening. Now there exists a means of
ascertaining whether the length of the day has undergone any variation;
this consists in examining, for each century, the arc of the celestial
sphere described by the moon during the interval of time which the
astronomers of the existing epoch called a day,--in other words, the
time required by the earth to effect a complete rotation on its axis,
the velocity of the moon being in fact independent of the time of the
earth's rotation.

Let us now, after the example of Laplace, take from the standard tables
the least considerable values, if you choose, of the expansions or
contractions which solid bodies experience from changes of temperature;
search then the annals of Grecian, Arabian, and modern astronomy for the
purpose of finding in them the angular velocity of the moon, and the
great geometer will prove, by incontrovertible evidence founded upon
these data, that during a period of two thousand years the mean
temperature of the earth has not varied to the extent of the hundredth
part of a degree of the centigrade thermometer. No eloquent declamation
is capable of resisting such a process of reasoning, or withstanding the
force of such numbers. The mathematics have been in all ages the
implacable adversaries of scientific romances.

The fall of bodies, if it