PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 685 



proach of two or three ? Then may he have witnessed the secret 

 of the mystery of the double and tri^)le stars ! When one of these 

 dimples approaches the vortex of another, the two begin to revolve 

 around each other; and in fact they must on approximation, act 

 upon each other as tivo loheels; so that a revolution of each 

 around the other m'ist immediately supervene, and increase in 

 rapidity, until by external pressure they are forced into one. If 

 such single neighboring nuclei were rotating, it would be precisely 

 a case of two contiguous whirlpools ; and how could revolutionary 

 motion be prevented ? Two such masses in approximate contact 

 must originate such a motion: as the principle of gravity draws 

 the nuclei nearer each other, the velocity of revolution must mani- 

 festly jncrease; and the two bodies would constitute themselves 

 into a stable system when the rapidity of revolution sufficed to 

 counterbalance their mutual attraction. 



It is known to mechanics, that a grindstone may be made to 

 revolve with a rapidity sufficient to cause splinters to fly from its 

 rim, and even the whole rim to break in pieces — indicating that 

 the centrifugal force of the rim with that velocity, more than coun- 

 terbalances the mutual attraction or cohesion of the particles of the 

 stone. Now if the rim, instead of beino- formed of brittle stone, 

 had consisted of an elastic belt, say of caoutchouc, Avhat would 

 result in such a case? Clearly a separation of the rim from the 

 mass of the rotating body; it would expand somewhat, just as the 

 orbit of a planet in a similar position; and, if other circumstances 

 permitted, it would revolve around the stone as a separate ring at 

 a distance where the balance or equilibrium of the forces would 

 be restored. 



First — As the separation of the rings resulted from the centrif- 

 ugal tendency of the particles composing them, and as this cen- 

 trifugal tendency must always be greatest at the equatorial region 

 of the rotatory mass, the rings must all lie nearly in the iplane of 

 that equator. Therefore, we are entitled to conclude, that into 

 whatever forms or bodies these rings may ultimately be resolved, 

 tJiese bodies must all lie in nearly one plane — the plane^ viz., of the 

 equator of the central globe. 



Secondly — The rings being circular — or, what is the same thing, 

 the motion of each particle composing them being circular, the 

 orbits or paths of whatever bodies are ultimately formed out of 

 them, must also be nearly circular. 



Thirdly — As the rings must continue to move as the nebula was 



