+------------------------------------+------+------+------+------+------+ | Nature. |42 Pr.| 32 | 24 | 18 | 12 | +------------------------------------+------+------+------+------+------+ | |Inches|Inches|Inches|Inches|Inches| | Exterior| 6.684| 6.105| 5.547| 5.04 | 4.4 | | Diameter of the shell Interior| 4.404| 4.005| 3.767| 3.4 | 2.8 | +------------------------------------+------+------+------+------+------+ | Thickness of metal | 1.14 | 1.05 | 0.89 | 0.82 | 0.8 | |Guns Exterior| 0.894| 0.894| 0.894| 0.832| 0.832| | Diameter of fuze hole Interior| 0.826| 0.826| 0.826| 0.769| 0.769| +------------------------------------+------+------+------+------+------+ | Powder for bursting oz. | 14 | 11 | 12 | 9 | 5½ | +------------------------------------+------+------+------+------+------+ | Exterior| 6.64 | 6.05 | 5.48 | 4.935| 4.295| | Diameter of shell Interior| 4.36 | 3.95 | 3.48 | 3.235| 2.695| | +------+------+------+------+------+ |Carron- Thickness of metal | 1.14 | 1.05 | 1. | 0.85 | 0.8 | | ades Shells Weight lbs. | | 22 | | 12 | | | Contains powder oz. | | 12½ | | 9 | | | Powder for bursting oz. | | 10 | | 7 | | +------------------------------------+------+------+------+------+------+ _The following Shells may also be fired from Guns._ Hand Grenades from 6 Prs. 4⅖ Shells ” 12 Prs. 5½ Shells ” 24 Prs. 8 Inch ” 68 Pr. Carronades. Shells may likewise be thrown from guns to short distances, in cases of necessity, though the bore be not of a diameter sufficient to admit the shell. For this purpose the gun may be elevated to any degree that will retain the shell upon its muzzle, which may be assisted by a small line going from the lugs of the shell round the neck of the gun. To produce a greater effect, the space between the shell and the charge may be filled with wads or other substance. LOMBARD. Shells are likewise sometimes quilted into grape. See the word _Shot_. For the method of proving shells. See _Proof_. _To find the Weight of a Shell of Iron._ Take ⁹/₆₄ of the difference of the cubes of the external and internal diameters for the weight of the shell. _To find how much Powder will fill a Shell._ Divide the cube of the internal diameter of the shell in inches by 57.3, for the pounds of powder. _To find the size of a Shell to contain a given Weight of Powder._ Multiply the pounds of powder by 57.3, and the cube root of the product will be the diameter in inches.