( 222 ) 



rum momenrorum ratione axium O X ec O Y 

 evanescant ; habemus igimr : 



P cof. y -f- P' cof. y' caet. "^ g "^ g' caec. 

 '" g -~ g' caec. = o : 

 id est: 



P cof y + P' cof y' + P" ro/! y^^ + caet. 



= o (4). 



Porro momenta virium P cof y cact. , ratio- 

 ne axeos O X , func : 



y.^^cofy, y'V' cofy', y" ^" cofy" cOiQi. , 

 Tnomenta virium g, g' , g ' caet. , funt : 



. yg^ y'g' ^ y" g" caec; 

 denique momenta virium "- g , " g' , "" g" t 

 habentur his productis : 



caet. ; 

 his omnibus momentis additis, erit fumma mo- 

 mentorum : 



yV cof y + y'V cofy' + caet. +3;^ + ji'^' 

 + caet. — yg "^ y' g' — caet. — zV cof /S 



— 2'P' cof (2' — caet. = o; 

 id est : 



P (y cof y - z cof (3) + P' (y' cof y' 



— z' cof^') + caet. = o ....... . (5). 



Quodfi adduntur momenta earundem virium , ad 

 axim O Y relaca , habemus eciam : 



R 



