3·5 cubed = 42·875, cube of diameter.
42·875 8 = 5·359 5·359 8 = ·669
5·359 + ·669 = 6·028 pounds. Weight required.
To find the weight of a leaden ball, its diameter being given.
Take ⅓ of the cube of the diameter, and from it subtract ⅓ of this third, and the remainder will be the weight, nearly.
Or, take 3/14 of the cube of the diameter.
Example.—What is the weight of a leaden ball whose diameter is 3·3 inches?
3·3 cubed = 35·937, cube of diameter.
35·937 3 = 11·979 11·979 3 = 3·993
11·979 - 3·993 = 7·986 pounds. Weight required.
To find the diameter of an iron shot, its weight being given.
Multiply the cube root of the shot’s weight by 1·923 for the diameter.
| Pr. | Cube root. | Diameter. | ||||
| 42 | 3·4760, &c. | { | } | 6·684, | &c. | |
| 32 | 3·1748 | { | Multiplied | } | 6·103 | ” |
| 24 | 2·8844 | { | by 1·923, | } | 5·545 | ” |
| 18 | 2·6207 | { | diameter | } | 5·038 | ” |
| 12 | 2·2894 | { | of a | } | 4·401 | ” |
| 9 | 2·0800 | { | 1 lb. | } | 3·999 | ” |
| 6 | 1·8171 | { | shot. | } | 3·494 | ” |
| 3 | 1·4422 | { | } | 2·772 | ” | |