60 



LIMIT TO THE REQUISITE THICKNESS OF FLOODGATES. 



74. Having calculated the numerical values of the thicknesses or 

 ordinates, corresponding to each foot in length, estimated from the 

 bottom where the pressure is a maximum, upwards to the summit 

 where it vanishes ; we shall now proceed to construct the section, in 

 order to exhibit the particular form which the preceding theory assigns. 



Let the straight line A B represent the perpen- 

 dicular depth of the flood-gate supporting the 

 fluid F, and whose vertical section is denoted by 

 the figure ABC, the exterior boundary of which is 

 the curve line ABC, and the greatest thickness, 

 or that at the bottom, equal to BC. 



Divide the depth AB into twenty five equal 

 parts, having an interval of one foot for each ; 

 then, through the several points of division, and parallel to the horizon, 

 draw straight lines, beginning at the bottom and proceeding upwards, 

 making these lines respectively equal to 12, 11.06, 10.156, 9.292, &c. 



