2- THE NEBULAU HYPOTHESIS. 



true that this change in the ratio, depending on tho degree 

 of contraction each planet has undergone, lias in no t\vo 

 cases Leon the same; yet we may fairly conclude that 

 where the ratio is still the greatest, it has been the greatest 

 from the beginning. The satellite-forming tendency Avhich 

 each planet had, will be approximately indicated by the 

 proportion now existing in it between the aggregating 

 power, and the power that has opposed aggregation. On 

 making the requisite calculations, a remarkable harmony 

 with this inference comes out. The following table shows 

 what fraction the centrifugal ii&amp;gt;ree is of tlic centripetal force 

 in every case ; and the relation which that fraction bears 

 to the number of satellites. 



Meremy. Venus. Earth. Mars. Jupiter. Saturn. I ranus. 

 Ill 1 111 



:;02 liJSU i;,v.) ;;^o 1 I C.--2 .i 



1 -1 8 4 (or G ac- 



i-Nitellito. Satellites. Satellites cording to 



and three Hors*chd.) 

 rings. 



Thus, taking as our standard of comparison the Karlh 

 *ith its one moon, we see that Mercury and Mars, in which 

 the centrifugal force is relatively less, have no moons. Ju 

 piter, in which it is far greater, has lour moons. Uranus, 

 in which it is greater still, has certainly lour, and probably 

 more than four. Saturn, in which it is the greatest, being 

 nearly one-sixth of gravity, has, including his rings, eleven 

 attendants. The only instance in which there is imperfect 

 conformity with observation is that of Venus. Here it ap 

 pears that the centrifugal force is relatively a very little, 

 greater than in the Karth ; and according to the hypothesis, 

 Venus ought, therefore, to have a satellite. Of this seem 

 ing anomaly there arc two explanations. Xot a lew astron 

 omers have asserted that Venus //. a satellite. Cassini, 

 Short, Montaigne of Limoges, Kocdkicr, and Montbarron, 

 professed to have seen it ; and Lambert calculated its ele- 



