Then 383·2752 × 30 = 11498·256, the content; which being divided by 277¼ (the number of cubic inches in a gallon) will give the number of gallons contained in the cask.
Thus 11498·256 277·25 = 41·4725, &c. Number of gallons required.
Note.-The content of any vessel in cubic feet, multiplied by 6·232 (or if in inches by ·003607) will give the number of imperial gallons it will contain.
EPITOME OF MENSURATION.
OF THE CIRCLE, CYLINDER, SPHERE, ETC.
1. The circle contains a greater area than any other plane figure, bounded by an equal perimeter, or outline.
2. The areas of circles are to each other as the squares of their diameters; any circle twice the diameter of another contains four times the area of the other.
3. The diameter of a circle being 1, its circumference equals 3·1416.
4. The diameter of a circle is equal to ·31831 of its circumference.
5. The square of the diameter of a circle being 1, its area equals ·7854.