[ 6>8 ] 
in It was collc6led in. the axis : tlie force with wliicii 
the plate repells the column, is proportional to 
D Q 3— ”_|^AC3— " — DA3 ~”j fuppofing the thicknel's 
of the plate and bafe of the column to be given. 
For, if DC is fuppofed to flow, the ccrrefponding 
fluxion of the repulflon is proportional to — 
DCxDC_ DC 
~ D C”-^ 
A,C3-”+DC3-«— DA3 
3— « 
ni flies.. 
J fluent of which^K, 
JJ A '' 
— n 
— , vaniflies when DC va- 
c o R 0 L L. r. 
If the length of the column is fo great that AC”"""^' 
is very fmall in refped of DC’^’-S the repuUion of. 
the plate on it is very nearly the fame as if the- 
column was infinitely continued. 
For by Lemma 8, A C3“”-|-DC3“" — D A.3~” 
differs very little in this cafe from A C 3~'* ; and if 
D C is infinite, it is cxadtly equal to it.. 
C o R o L L. IL 
If AC’^’ is very fmall in refpe^ of anch 
the point E be taken in DC fuch that EC” fliall. 
be very fmall in refped of AC”~S the repulfion of 
the plate on the fmall part of the column EC, is to- 
its repulfion on the whole column D C, very nearly 
as EC^~" to AC*-"'- 
L E M M A\ 
