320 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
in which G is the centre of gravity of the points M,,, assumed 
to be of mass m,. 
But the points M, can be classified in two categories M, 
and M; according to whether they lie between O and G or 
between G and P of the abcissa p 
(, 
vi 
© 
For the M; points 
(517-3) 
GM, < OG . 
Again, if the 0, do not decline too rapidly, G will be to 
the right of the centre of the segment OP, and the image O’ 
of O with respect to G will be to the right of P. Then we will 
have 
(517-4) 
GM. < 0G 
so that 
(517-5) 
1 Em, GM° 
2 OG'Em. 
Thus under the assumptions made. that is to sav if 
(517-6) 
[S58 
"111 Allais - pag. 224