But as it is desirable that every division on the gun-deck should be exercised in mounting and dismounting its guns, a hole may be made in the deck above each division and bouched with a composition screw-tap.
The purchase-falls should not be less than three and a half inches in size, and should be made of Manilla rope, of sufficient length to reeve full, the gun being supposed to be on deck and the upper blocks in place, allowing also sufficient end for splicing in the thimbles and hitching the standing part of the purchase when rove.
An iron thimble, large enough to hook the double-block of a side or train tackle, is spliced into the end of each purchase-fall.
SELVAGEE WADS.
214. Selvagee wads are made by the wad-machine at the Navy Yards. This consists of pairs of disks adapted to each calibre of guns, which being placed face to face on a spindle and keyed, present an annular score, grooved in such a way as to make, when filled, a grommet of the requisite size. Transverse notches are cut in the circumference of the disks to the bottom of the score, for the convenience of marling the wad before taking it off the mould.
Lith. by J.F. Gedney, Washn. C.K. Stellwagen, del.
In making the wad, the end of a rope-yarn is fixed in the score, and the mould is turned by a crank until the score is filled. The grommet thus formed is marled like a selvagee strap, and a section of about an inch is taken out of it, in order to make the wad, when swelled by dampness, enter the bore of the gun readily.
Selvagee wads should be made neither too hard nor too soft; and to avoid either of these extremes, a sufficient number of hitches only will be taken to give the wad the consistency required for service.
Sections of one-third or one-fourth of these wads will answer as well, in case of need.