The republic. [volume] (Washington [D.C.]) 1849-1853, 1849-08-11


MEssRs. EDIroRs As the total extinction OF
inns valuable tree is considered certain at no distant
day, and a. our navy is considered the present and
future bulwark Of our safety, as a commercial ma
ton, Il is not thought inappropriate TO make few
remarks on the process of decay in those woods
which are principally used in the construction of
our ships of war and commerce.
The oaks of North America as described by
Andrew Michaux, consist of twenty species
and varietIes those which are the most useful and
least liable 10 decay the live oak white oak
post oak, black oak, chestnut oak, chestnut white
oak, and rock chestnut oak The one which is
considered the most useful, and stands al the head
of the above iist is the live oak (queyeus pirens
This Tree is found growing from latitude 37o to
Florida, where II is the most abundant and thence
westward to the mouth Of the Sabine river, gene
rally growing not more than Is or 20 miles from
the ocean. IL is perennial tree, Of slow growth,
like The rest of its congeners, but thryes the hest
under the care and cultivation Of man.
AS this tree contains less of the causes OF decom-
positlon-as sugar, albumen, and starch--than any
of the species heretofore described, we shall speak
of the process of decay, (termed dry rot, being
constant theme Of scientific inquiries for many
years among our most eminent chemists, of which
the most elaborate Investigations have been made,
in order TO ascertain the chemical effects of air, heat
light and moisture on our oak tlmbers, that have
been previously prepared and appropriated to use
for bodybuilding.
We do not have the presumption at present to
offer any preservallve means that would counteract
the effects of this dreaded enemy to our national
purse, but simply TO throw out some hints that
may, in the future, be raying point to others
who can claim the precedence over their more
humble brothers in the profession. The modern
use Of iron in the construction of marine vessels
has been thought, at a subsequent. period, would
supersede that Of wood-having, then, nothing but
oxides to contend with instead of fungi but we do
not believe the formerw supersede that the latter
As the grand engine of navigation is deterioratng
every day from the effects ofdry rot, may be asked
Whatist the dry rot' and how long has il been known
to affect the tmbers of vessels and the cause of this
effect? In answer to the former, we suppose the
dry rot is caused by the spontaneous decomposi-
ton Of the vegetable albumen, which acts as fer
ment on the other constituent principles that may
be present IN the wood, sugar and starch, which
disintegraes the fbres of the wood and acceerates
the growth of mushrooms by the formation of am
monlacal salts. Of these fungi there two spe-
cies as the rylostrona gigantelm which grows in
the timber. like thin broad patch of yellow leather
and the se,p,Ia distruens, which is not large, Of
red color, and whitsh at the edge. As the cause
of dry rot proceeds from an excess of vegetable
albumen in those woods that have been in modern
use for ahip-building, we may answer the latter
questions by saying that the primitive oaks of Great
Britain, and those Of our country, which were used
in the early construction of their navies, were
not so rich in albumnous matter as the oaks of
secondary growth and different locations are now.
Therefore the dry rot and fungous growths in
such timber were not known, nor ever would have
been had we the timber of those primitive forests
of Great Britain and those of our country 1t
will be proper to aude to the fact, that the cause
Of dry rot often proceeds from the negligence and
want of knowledge in the selection of those trees
which resist the effects of time and exposure with
out the process of decay Such is position; and
without further comment, we proceed to illustrate
many points connected with the subject under con-
sideration, as it is one of the most important to
which the attention of maritime people can be
turned.
With all the natural immunities against sponta-
neous decomposition in the live oak, we should not
overlook the locality of its growth age, and season of
cutting for ship timber. This is necessary precau-
ton which is applicable to the whole tribe of oaks,
that will be included under head in the sequel
of our remarks. The best localities for the seec-
ton Of durable timber from those trees elevated
regions, high table-lands, and an open country,
where they are not overshadowed by other growths
They should stand where there is ample room for
their branches, with free of air. heat, and
light, on all sides, often seen on the boundary
of some plantation, or as ornaments which
ate the mansion of the planter, or suchlike places.
The woody 6bres of such trees are more dense
they contain more carbon and astringent qualities,
with less vegetable albumen. Whereas, to the con-
trary Of this, should such timber be cut in low wet
grounds, il would be liable decay from the causes
mentioned as there would be an excess of those
constituent principles already mentioned and is
also referable to any of the species Of oaks that
are found growing compact in shady places, RAJ
vines, as such woods are liable to decay, the fbres
and structure being softer, and favorably disposed
to be affected by the dry rot, deleerous to our
navies.
The age Of the oaks is next to be considered.
They generally attain their maximum height and
fun development at the age of forty or fifty years,
and after that period progress but slowly until they
arrive al an advanced age, two or three hundred
years. Those Of the live oak that can be best
recommended for durable timber are such as have
arrived TO the period Of hundred years more,
If the constitution OF the trees is sound, and WIS.,
ibie decay is present il will be maintained that
the maturity of all the species Of oaks should be
considered before used or appropriated for ship.
building; for it is at this period the strength and
durability Of the wood is fully developed, and the
longitudinal fbres tough and resisting. AS the
slbuminous matter of which we have spoken is a
nrogenized compound, il is of a putrescible ma
ture, and therefore forms food for insects which
penetrate the wood in various directions, ad-
hitting air and water to the interior of the tim
ber IL is evident that this chemical action, fer
mentatiye process, must be favored by external
causes, the location in which the wood is placed.
The close opposition, in the dense mass of TIM
bers that in the hull Of battle ship of the
line on the stocks, is considered as favorable TO this
action, although there ure no doubts but what the
germ Of the disease is lurking in the tmbers pre-
yious to its The local sites of navy yards,
where there must be proper depth Of water, una
voidably place the timber in Typographical sit
uation that is unfavorable the preservation of the
wood, as heat and moisture accelerate the chemical
action, and promote the fungous growths where
nutrition depends on the chemical changes hereto
fore mentioned
Could we always find a suitable hydrognphical
station for a navy yard, where combined with its
facilities there was dryness and purity Of atmo-
sphere, many of the causes that decompose the ma
terials for building would be prevented. But as
such locations cannot always be found in the sur
veys for such stations we must patiently submit
TO the injurious effects of heat and damp a;mo-
sphere. however well guarded and ventilated the
ships may be in their sheltered positions; although
il is Of the highest importance that the geographical
positions Of such places well understood and
taken into consderation--as rivers, boys, marshes,
mean standard Of the thermometer, barometer, hy-
grometer, and mean quantity Of rain
The proper season for cutting such timber will