THEIR ARRANGEMENTS AND FORMATION. 13 



river flowing between irregular banks. There we not only 

 see single dimples rotating and passing onward, results of 

 that obliquity in the meeting of currents which is thought 

 to have set solar systems in motion ; but often two or more 

 of these dynamic microcosms will come within range of a 

 mutual influence, and go on wheeling around each other. 

 These fantastic eddies, which the musing poet will some- 

 times watch abstractedly for an hour, little thinking of the 

 laws which produce and connect them, form an illustration 

 of the mechanism of binary and ternary stars, and bring 

 an unexpected aid to a theory of the history of the heavenly 

 spaces. 



A remarkable approximation has also been made to what 

 may be called an experimental verification of this cosmogony, 

 by a living professor, M. Plateau, of Ghent. Divested of 

 technical terms, the experiment was nearly as follows : 

 Placing a mixture of water and alcohol in a glass box, and 

 therein a small quantity of olive oil of density precisely equal 

 to the mixture, we have in the latter a liquid mass relieved from 

 the operation of gravity, and free to take the exterior form given 

 by the forces which may act upon it. In point of fact, the oil, 

 by virtue of the law of molecular attraction, instantly takes a 

 globular form. 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 in rotation. " We 

 then presently see the sphere flatten at its poles and swell out at 

 its equator, and thus realize on a small scale an effect which is 

 admitted to have taken place in the planets." The spherifyiug 

 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. Quick- 

 ening the rotation makes the figure more oblately spheroidal. 

 When it conies 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 rotation, stretching out continually in a horizonal direc- 

 tion, and finally, abandoning the disc, is transformed into a per- 

 fectly regular ring." At first, this remains connected with the 

 disc by a thin pellicle of oil ; which, however, on the disc 

 being stopped, breaks and disappears, and the ring then be- 

 comes completely disengaged. The only observable difference 

 between this ring and that of Saturn, is that it is rounded, 



