PORT-SILLS.
Inches. Inches.

Height of centre of lower bolt from deck 14.75 10.75
Distance between the bolts 3.75 3.75
Distance of centre of 1st bolt from side
of port 14. 14.
Distance of centre of 2d bolt from side
of port 22. 22.
Distance of centre of training-bolt from
side of port 36. 36.
Height of training-bolt from deck 21. 14. & 16.
Height of securing-bolt (side-tackle
bolt) above port-sill 8. 8.

For IX-in. guns, the port-sill should not be less than 20 inches in
height, and no port-sill less than 16 inches; otherwise, the carriages
will not give sufficient elevation, and the position of the Gun
Captain in aiming is exceedingly awkward and inconvenient.

Scraping and staining gun-carriages or keeping them bright is
prohibited; they should be kept well painted, and the trucks,
axletrees, and trunnion-holes oiled.

All new work shall be primed with red-lead.

Wrought-iron Broadside carriages, for IX-inch, new 8-in. of 6,500
lbs., and 32-pdr. of 4,500 lbs. shell-guns, have been designed by the
Ordnance Bureau, submitted to trial with success, and are being issued
for service at sea.

GUN-GEAR.

208. Breechings for all guns are to be made of the best hemp, of
three-stranded rope, shroud-laid, and soft; and for smooth-bore guns
not to measure less than seven and a half nor more than eight inches
in the coil, excepting those for IX-inch guns, which are to measure
nine and a half inches, and for XI-inch ten and a half inches.

209. The breeching-bolts must never be of less dimensions than those
prescribed by regulation, and there must be double sets for the IX and
XI inch guns.

210. In fitting breechings, a thimble is to be spliced into one end,
the strands stuck through twice, and marled down. A thimble is to be
turned into the other end, so that the length of the breeching may be
conveniently altered. Thus fitted, when the gun is run in and
levelled, breechings must be long enough to allow the muzzle of the
gun to come a foot inside of the upper port-sill, if the breadth of
the vessel will allow it. With guns of violent recoil this distance
may be advantageously doubled, where there is room enough, as