RULES AND MEMORANDA FOR THE GOVERNMENT OF INSPECTORS.
68. All shot and shells for the naval service must be—
1st. Made from gray or mottled charcoal pig-iron.
2d. This iron most not be blasted with anthracite coal.
3d. It must be poured into sand moulds.
69. After being cast in this manner, the shot and shells must be—
1st. Spherical.
2d. Smooth on the surface.
3d. Free from the defects named in the following rules for the use of the inspecting instruments:
FOR SHOT.
70. Inspecting Instruments.—One large, small, and one medium ring gauge, and one cylinder-gauge for each calibre. The cylinder-gauge shall have the same diameter as the large gauge, made of cast iron, and three calibres in length. One hammer weighing two pounds, and having a flat face and a conical point; one searcher, of steel wire, with a handle; one pair of calipers and standard scale; one cold chisel; steel punches.
71. After having been well cleaned, each shot is placed upon a table, and examined to see that its surface is smooth, and that the metal is sound and free from seams, flaws, and blisters. If clusters of cavities or small holes appear on the surface, strike the point of the hammer into them, and ascertain their depth with the searcher. If the depth of the cavity exceeds 0.2 inch, the shot shall be rejected; it shall also be rejected if any attempt is made to conceal defects by plugging or filling holes in any mode whatever.
72. The shot must pass in every direction through the large gauge, and not at all through the small one; the calipers and scale will determine exactly the difference of diameters of the same projectile.
73. The ring and cylinder gauges shall be examined before each inspection, and when found to have enlarged 0.01 of an inch, must be laid aside and marked as unserviceable.