Or, multiply the cube of the diameter by 11, and divide by 21 for the quantity in half ounces.
Example.—How much powder will fill a shell, whose internal diameter is 7 inches?
7 cubed = 343.
343 57·3 = 6 pounds nearly. Powder required.
To find the side of a cubical box to contain a given quantity of powder.[57]
Multiply the weight in pounds by 30, and the cube root of the product will be the side of the box in inches.
Example.—Required the side of a cubical box to hold 50 pounds of powder?
50 × 30 = 1500, the cube root of which is 11·44, which will be the side of the box in inches.
To find the quantity of powder to fill the chamber of a mortar, or howitzer.
Multiply the content of the chamber in inches by 55, and divide the product by 1728, and the quotient will be the quantity of powder in pounds.