DRY ROT IN SHIPS. 253
"likely to point out the state of air favourable for the growth of Fungi.
"I have found by experiment that Wood will rot and Fungi grow at
"800° or 900°.
"I have ventured to declare that the Queen Charlotte may be
"repaired, because I have hopes that the further progress of vegeta-
"tion may be stopped, but unusual caution is requisite with her from
"the circumstance of the Timber of which she is built being in a state
"fit for vegetation whenever it is placed in a favourable situation.
"In the first place I should recommend the removal of every ob-
"struction to a free current of air through and around every part pos-
"sible and stretching an awning over the whole ship at some distance
"above the deck and so placed as to keep off rain without dropping
"upon the vessel and at the same time to admit a current of air beneath
"it; the awnings at present in use are not sufficiently extensive, they
"are pervious to rain and lie so close to the deck that there is some
"reason to fear that by confining moisture they may promote destruc-
tive fermentation, the immediate cause of the rot, which is the more
"probable in the present favourable season for the growth of Fungi.
"Thus, by a current of air I would endeavour to remove all moisture
"and so leave no nourishment for the parasite ; I would even suggest
"the appointment of some able person to see the various parts as
"thoroughly dried as possible, by air, before any fresh wood is put in.
"I should object to the use of artificial heat as likely to increase the
"temperature of the moisture and consequently the fermentation with-
''out removing it; but a rapid draught of cold air which may be caused
"by stoves so placed as not to heat the Timber, will be useful to dry
"such parts as the air can otherwise scarcely have access to; this
"kind of ventilation Mr. Lukin has already employed with success.
"I would next suggest the. necessity of using the best seasoned
''Timber in the repair and to keep this as dry as possible by laying
''it dry and open and raised from the ground near the workmen and
''should any part of the Ship have got wet by any means it will be
"proper to let it dry before fresh wood is placed over it ; and care
"should be taken that no hollows are covered up that contain shavings,
"sawdust or any dirt capable of retaining, or absorbing moisture. As
''it appears necessary to put the boiler planks on while moist it will
''be proper to use every endeavour to let the planks have air enough to
"dry internally, thus they may be put on alternately, leaving spaces
"to be filled by intermediate ones after the first set have had sufficient
"time to dry ; two or three planks may be kept off till all the others
"are supposed to be thoroughly dry that when the whole is closed, as
"little moisture as possible may be confined. It will also be requisite,
"at this season of the year, particularly, not to paint any part that is
"not previously as dry as possible, so that the oil may rather penetrate
"the wood itself than drive moisture before it.
"I conceive that any impregnation of the wood is unnecessary, if the
''wood be properly dried ; and many acid or saline impregnations I
"have heard recommended as perfect cures, are certainly detrimental to
"the wood, bolts and workmen.
"The Pitch Pine that is to be replaced should be perfectly cleared