[ 385 ] 
§ X. If we take nothing but the inoft advanta- 
geous pofition into conftderation, and preferve the 
greateA effect entire, it follows that the angle BCD 
(fig. 6.) between two float-boards mud be fuch that 
E (hould enter the water at the inflant when AB 
quits the vertical, fo that the coflne of that angle be 
= -j in confequence of which the following table 
may be conArudted, (hewing what the number of 
float- boards (hould be for a given ratio between 
f and a. 
r 4 float-boards, 
we have/' 0, 
5 
0,3090a 
6 
0,5000 a 
7 
0,6236a 
8 
0,7071a 
9 
0,7660a 
10 
0,8090a 
1 2 
0,8669a 
14 
0,9009a 
16 
0,9239a 
3 8 
0,9397a 
20 
0,9510a 
&L\ 
&c. 
§ XI. Certain authors treating of hydraulics, 
have in this part thereof given the fame table, as 
containing the true number of float-boards the wheel 
(hould confiA of: but we have feen upon what prin- 
ciple it was formed, and that it was only to preferve 
entirely the effect of the vertical float-board ; from 
whence it follows not that the number of float- 
boards which it afligns (hould be the moft advanta- 
Vol. LVII. Ddd geous. 
