rting rivets with large heads, so as to cover up the imperfection. If
the top of the furnace be bent down, from the boiler having been
accidentally allowed to get short of water, it may be set up again by a
screw jack,--a fire of wood having been previously made beneath the injured
plate; but it will in general be nearly as expeditious a course to remove
the plate and introduce a new one, and the result will be more
satisfactory.

735. _Q._--In the case of the chimney being carried away by shot or
otherwise, what course would you pursue?

_A._--In some cases of collision, the funnel is carried away and lost
overboard, and such cases are among the most difficult for which a remedy
can be sought. If flame come out of the chimney when the funnel is knocked
away, so as to incur the risk of setting the ship on fire, the uptake of
the boiler must be covered over with an iron plate, or be sufficiently
covered to prevent such injury. A temporary chimney must then be made of
such materials as are on board the ship. If there are bricks and clay or
lime on board, a square chimney may be built with them, or, if there be
sheet iron plates on board, a square chimney may be constructed of them. In
the absence of such materials, the awning stanchions may be set up round
the chimney, and chain rove in through among them in the manner of wicker
work, so as to make an iron wicker chimney, which may then be plastered
outside with wet ashes mixed with clay, flour, or any other material that
will give the ashes cohesion. War steamers should carry short spare
funnels, which may easily be set up should the original funnel be shot
away; and if a jet of steam be let into the chimney, a very short and small
funnel will suffice for the purpose of draught.

MANAGEMENT OF MARINE ENGINES.

736. _Q._--What are the most important of the points which suggest
themselves to you in connection with the management of marine engines?

_A._--The attendants upon engines should prepare themselves for any
casualty that may arise, by considering possible cases of derangement, and
deciding In what way they would act should certain accidents occur. The
course to be pursued must have reference to particular engines, and no
general rules can therefore be given; but every marine engineer should be
prepared with the measures to be pursued in the emergencies in which he may
be called upon to act, and where everything may depend upon his energy and
decision.

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