for Preserving Corn on Ship-board . 311 
stroke, and that again by the number of strokes in any 
given time. 
To find the area of a circle, and the solidity of a cy- 
linder raised on that circle, Archimedes gives the follow- 
ing proportion : — 
As 1 is to .785398 decimal parts, so is the square of 
the diameter to the area of the circle. 
And, as 1 is to .785398, so is the square of the diame- 
ter, multiplied by the height, to the solidity of the 
cylinder. 
The cubical contents, both of the cylinders and tubes, 
are found in the same manner ; their difference consist- 
ing not in shape, but solidity, the latter being hollow. 
Then, to find the contents of a cylindrical vessel whose 
internal diameter is ten inches, multiply that into itself, 
and the square thus obtained, multiplied by .7854, will 
give the contents of the circle in cubic inches ; which, 
multiplied again by twenty-four inches or lengths of the 
stroke, being the proportion of the barrel filled with air, 
gives in cubic inches the amount of each discharge on 
the descent of the piston. As thus : 
Inches. 
Internal diameter of the pump or tube 1 0 
X 10 
“ 100, or square of the diameter; 
which, multiplied by .7854, to bring the contents of 
the square to the con- 
tents of the circle. 
Which, multiplied by the 
length of the stroke 
! h '} 
78,5400 Contents of the area of 
the circle. 
24 inches, produces 1884 
cubic inches. 
3141600 
1570800 
1884.9600 
which, divided by 231)1884.9600(8.1600 gallons, which is 
viz. the number of cubic inches in a — — ■ -J^thsmore than 
wine gallon, quotes 8 galls. 369 8 gallons at a 
— - — - stroke ; allow 
1386 these decimals 
— — - for waste of air 
