326 Note on Surfaces of the Second Order. 



From the expression for the attraction of a shell we can find, 

 by another integration, the attraction of the entire ellipsoid when 

 the law of force is that of nature. And thus the well-known 

 problem of the integral calculus, in which it is proposed to deter- 

 mine directly the attraction of an ellipsoid on an external point, 

 without employing the theorem of Ivory to evade the difficulty, 

 is solved in what appears to be the simplest manner. 



