22]
57. How are cannon in our service marked?
As follows, viz: The number of the gun and the initials of the inspector’s name on the face of the muzzle,—the numbers in a separate series for each kind and calibre at each foundry; the initial letters of the name of the founder, and of the foundry, on the end of the right trunnion; the year of the fabrication on the end of the left trunnion; the foundry number on the end of the right rimbase, above the trunnion; the weight of the piece in pounds on the base of the breech; the letters U. S. on the upper surface of the piece, near the end of the reinforce.
58. What marks are used to designate condemned pieces?
Pieces rejected on inspection are marked X C on the face of the muzzle; if condemned for erroneous dimensions which cannot be remedied, add X D; if by powder proof, X P; if by water proof, X W.
59. What are the kinds of proof which artillery must undergo, before being received into the service?
1st. They are gauged as to their several dimensions, internal and external; as to justness and position of the bore, the chamber, vent, trunnions, &c.
2d. They are fired with a regulated charge of powder and shot, being afterwards searched to discover irregularities or holes produced by the firing.
3d. By means of engines, an endeavor is made to force water through them.
4th. They are examined internally, by means of light reflected from a mirror.