200. The magazine is to be lighted by means of one regulation-lamp, to
correspond with each alley of the magazine-room, placed in a box
arranged for the purpose. This box, of which a portion of the magazine
bulkhead forms a part, is to be lined, internally, with soldered
sheets of copper, and have a few inches of water in it whenever the
lamp is lighted. The entrance to it is at the top, through a scuttle
in the deck large enough to admit the lamp. For single-decked vessels
this scuttle may be surrounded by a composition coaming pierced with
holes one-fourth of an inch in diameter, on the forward and after
sides near the top. The cover must be so arranged that, when placed in
one position, all the holes will be closed--by turning it half round,
they are all open; thus supplying air to the lamp and carrying off
smoke. In the portion of the magazine bulkhead just alluded to, and so
as to throw as much light as possible into the magazine-room, an
opening with great bevelling is to be cut, which is to be covered by
two plane glasses of suitable thickness, somewhat separated from each
other, one of which, that next to the lamp, must be permanently fixed;
and the other, or that next to the magazine, is to be let into a
wooden frame so that it may be easily removed, and thus both glasses
cleaned at any time with convenience and safety. The glasses are to be
held in place by brass screws, after being closely fitted and having
their edges made perfectly tight. A small dome or reversed funnel of
copper, where it can be conveniently done, is to be placed above the
lamp and fitted with a pipe of the same metal to convey the smoke off.
This pipe may pass up through the covering of the light-box, which is
to have a plug-hole, lined with brass, for the purpose, and then led
farther, if necessary, taking care, however, to consult perfect safety
throughout.