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receive it other wife than obliquely, ana the effect vCdd 
diminifh till the angle formed by two neighbouring 
float-boards be bifeded exadly by the vertical, 
which will render the firft entirely ulelefs ; arter 
which the effed will increafe anew, and will become 
again greateft, when the lecond float-board is got to 
the vertical j fo that in order to fix upon the mod; ad- 
vantageous number of float-boards, regard mufl be 
had to the fum of the different effeds for all the 
lituations of the float-boards during one whole turn 
of the wheel. 
Whence it follows that in this cafe, wherein they 
are fuppofed very fmall, the greater their number is, 
the greater will be the fum total of the effeds, fince, 
if that number were infinite, there would be a float- 
board in a vertical pofition every inftant. . 
§ IX. This will no longer hold good, if the 
height of the float-boards be mote confiucrable, and 
it be found neceflary to take the different velocity of 
their different points into confideration ; by com- 
paring (fig. 4-) the preffure on FE with that on the 
portion GO, they will he found no longer equal, pas 
in the foregoing cafe ; it is true that the fame quantity 
of fluid ads on thefe two planes, and the di fad van- 
tage which FE has by receiving the impulfe more 
obliquely, is exadly compenlated, as before, oy tnc 
length of the lever,, but the difference ariies from tne 
different velocity of the correfponding points of b E 
and GO 5 thofe’velocities are in the ratio of CT to 
CG, or as cof. ACG to cof. ACE, which fhews 
that the effed of FE is always lcfs than that cn 
GO, and confequently the effed mud be dimi- 
nifhed, by adding a greater number or fioat-boaids 5 
