not tolerate that pages should be wasted in merely discussing to whom
we owe each formula, and to whom each deduction from such formula is
due. He would rather endeavour to produce as complete a picture as
he possibly could of the celestial mechanics, and whether it were by
means of his mathematics alone, or whether the discoveries of others
may have contributed in any degree to the result, is a matter so
infinitesimally insignificant in comparison with the grandeur of his
subject that he would altogether neglect it. "If Lagrange should
think," Laplace might say, "that his discoveries had been unduly
appropriated, the proper course would be for him to do exactly what I
have done. Let him also write a "Mecanique Celeste," let him employ
those consummate talents which he possesses in developing his noble
subject to the utmost. Let him utilise every result that I or any
other mathematician have arrived at, but not trouble himself unduly
with unimportant historical details as to who discovered this, and
who discovered that; let him produce such a work as he could write,
and I shall heartily welcome it as a splendid contribution to our
science." Certain it is that Laplace and Lagrange continued the best
of friends, and on the death of the latter it was Laplace who was
summoned to deliver the funeral oration at the grave of his great
rival.

The investigations of Laplace are, generally speaking, of too
technical a character to make it possible to set forth any account of
them in such a work as the present. He did publish, however, one
treatise, called the "Systeme du Monde," in which, without
introducing mathematical symbols, he was able to give a general
account of the theories of the celestial movements, and of the
discoveries to which he and others had been led. In this work the
great French astronomer sketched for the first time that remarkable