towards their own centre of gravity.

"In the last place, as a natural conclusion of the
former cases, there will be formed great cavities or
vacancies by the retreating of the stars towards the
various centres which attract them."[1]


Looking forward, it appears that the time must come
when all the suns of a system will be drawn together
and destroyed by impact at a common centre. Already,
it seems to Herschel, the thickest clusters have
"outlived their usefulness" and are verging towards
their doom.

But again, other nebulae present an appearance suggestive
of an opposite condition. They are not resolvable
into stars, but present an almost uniform appearance
throughout, and are hence believed to be
composed of a shining fluid, which in some instances is
seen to be condensed at the centre into a glowing mass.
In such a nebula Herschel thinks he sees a sun in
process of formation.


THE NEBULAR HYPOTHESIS OF KANT

Taken together, these two conceptions outline a majestic
cycle of world formation and world destruction--
a broad scheme of cosmogony, such as had been vaguely