this vapour-like mass assumed, in some way, a rotatory motion. The problem which he undertook to solve may be thus stated—Given a nebulous mass in rotation, to shew how the various bodies of our system might be evolved from it, and their regularity of motion and disposition accounted for. The solution consists in supposing the rotating nebula to cool and condense, so that the central portion increases its rate of rotation, while an equatorial zone or ring of vapour is left behind, which rotates as a body separate from the central mass. A conception of the process may be formed by supposing the solid globe of the earth to contract its dimensions very much. A corresponding increase in the rate of its rotation would consequently follow, and the atmosphere would be left behind, whenever the centrifugal force exactly balanced the force of gravity. The atmosphere thus abandoned, would form a gaseous body revolving round the earth.
The successive rings abandoned by the rotatory nebula, would continue to rotate in the same direction as before. But it would be highly improbable that the integrity of each should be preserved. From inequalities in the internal forces, the ring would most probably be broken up, and form distinct globular masses, all revolving in the former plane of the ring, and in the same direction. These globes would most likely attract each other, and form one nebulous mass, the germ of some future planet. Now this mass would exhibit the same phenomena as the original
