robable. Each of them
accordingly broke in its turn into several masses, which were plainly
endued with a movement of rotation, coinciding in direction with the
common movement of revolution, and which in consequence of their
fluidity assumed spheroidal forms.

In order, then, that one of those spheroids might absorb all the others
belonging to the same ring, it will be sufficient to assign to it a mass
greater than that of any other spheroid.

Each of the planets, while in the vaporous condition to which we have
just alluded, would manifestly have a central nucleus gradually
increasing in magnitude and mass, and an atmosphere offering, at its
successive limits, phenomena entirely similar to those which the solar
atmosphere, properly so called, had exhibited. We here witness the birth
of satellites, and that of the ring of Saturn.

The system, of which I have just given an imperfect sketch, has for its
object to show how a nebula endued with a general movement of rotation
must eventually transform itself into a very luminous central nucleus (a
sun) and into a series of distinct spheroidal planets, situate at
considerable distances from each other, revolving all around the central
sun in the direction of the original movement of the nebula; how these
planets ought also to have movements of rotation operating in similar
directions; how, finally, the satellites, when any of such are formed,
cannot fail to revolve upon their axes and around their respective
primaries, in the direction of rotation of the planets and of their
movement of revolution around the sun.

We have just found, conformably to the principles of mechanics, the
forces with which the particles of the nebula were originally endued, in
the movements of rotation and revolution of the compact and distinct
masses which these particles have brought into existence by their
condensation. But we have thereby achieved only a single step. The
primitive movement of rotation of the nebula is not connected with the
simple attraction of the particles. This movement seems to imply the
action of a primordial impulsive force.

Laplace is far from adopting, in this respect, the almost universal
opinion of philosophers and mathematicians. He does not suppose that the
mutual attractions of originally immovable bodies must ultimately reduce
all the bodies to a state of rest around their common centre of gravity.
He maintains, on the contrary, that three bodies, in a state