214 Proceedings of the Royal Irish Academy. 



and Ui, &c., u^, certain constants pertaining to those screws, and 

 depending upon the mass of the body and its freedom. 

 "We have, therefore, 



-^^ {iiuA) = - t:'2hL, 



whence, integrating during the small time t, 



Jo 

 so that 6i, &c., $e, are proportional respectively to 



-, (XC, — r. 



Ux tin 



Q. E. D. 



