r
a bar of wood to ship and unship with facility, will be provided for
each tier of tanks, on both sides of the alleys, to secure them from
getting out of place when the ship rolls.

The Inspector of Ordnance will furnish the commander of the ship with
an exact plan of the magazine and shell-rooms, which shall be returned
to the Inspector of the Yard at which the ship refits or is placed in
ordinary, with any suggestions the Commander may have to make relative
to practicable changes which will render the service more safe or
convenient.

SHELL-ROOMS.

202. Rooms for the stowage of loaded shells require the same care in
construction and protection against an enemy's shot, and in provision
for lighting and flooding, as magazines. Therefore, they should always
be built with reference to these objects, as well as to affording room
enough to accommodate conveniently the number of loaded shells allowed
in their boxes, stowed in bulk. Each should have one light, arranged
like those for magazines.

203. In vessels partially armed with shell-guns, the best place,
perhaps, for these rooms is immediately forward of the spirit-room,
but not communicating with it; and in those armed entirely with such
guns, the additional shell-rooms necessary may be, perhaps, more
conveniently placed abaft, and adjoining the delivering-passage of the
forward magazine, than elsewhere.

204. With the introduction of rifled cannon, and various special
projectiles, it is essential to devote more care to the stowage of
shells, in order to avoid confusion in battle. Not only each kind and
calibre, but each length of fuze, is to be stowed in separate tiers.

DAMPNESS OF MAGAZINES AND SHELL-ROOMS.

205. Sponge clipped in a solution of salt water, dried and weighed, is
a means of ascertaining if dampness exists in these places. If it
become heavier, the room is damp.

VENTILATION.

206. Provision must be made, by means of grating-hatches, for
sufficient ventilation in action, to supply the magazine-men with
fresh air, and allow the dampness caused by perspiration to pass off;
and fan-blowers are to be fitted to increase the supply of fresh air,
and assist the ventilation. The magazine should be opened and aired,
at least once a fortnight, for a few hours, on bright, clear days.

[Illustration: SPACES REQUIRED for working DIFFERENT CLASSES OF GUNS
ON TRUCK CARRIAGES. (_with muzzle 18 in. inside of centre of Port_) C.K.
Stellwagen, del. Li