NEBULAR HYPOTHESIS. 15 



it. In point of fact, the oil instantly takes a 

 globular form by virtue of molecular attraction. 

 A vertical axis being introduced through the 

 box, with a small disc upon it, so arranged that 

 its centre is coincident with the centre of the 

 globe of oil, we turn the axis at a slow rate, and 

 thus set the oil sphere into rotation. " We then 

 presently see the sphere flatten at its poles and 

 swell out at its equator, and we thus realize, on a 

 small scale, an effect which is admitted to have 

 taken place in the planets." The spherifying 

 forces are of different natures, that of molecular 

 attraction in the case of the oil, and of universal 

 attraction in that of the planet, but the results are 

 •• analogous, if not identical." Quickening the 

 rotation makes the figure more oblately spheroidal. 

 When it comes to be so quick as two or three 

 turns in a second, " the liquid sphere first takes 

 rapidly its maximum of flattening, then becomes 

 hollow above and below, around the axis of rota- 

 tion, stretching out continually in a horizontal 

 direction, and finally, abandoning the disc, is 

 transformed into a perfectly regular ring^ At first 

 this remains connected with the disc by a thin 

 pellicle of oil ; but on the disc being stopped this 



