Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1846-10-31

The effect Of temperature in the expansion and dlaaon Of
all bodies is universal law Of nature and worthy of
sderaon in the present inquiry. The of heat
has not the effect all bodies, inasmuch liquids
pand than metals and air form bodies than either
and under the application of the quantity of caoc. By
the introduction Of intermediate body, that Of quicksilver
the only metal that retains fluid state the atmospheric
peature and combining in convenient instrument known
thermometer, and making that general standard
graduate the relative quantity Of caoc in body and of
consequence, the expansion and contraction Of
tails when exposed TO different degrees of heat and cold with
sufficient accuracy to enable lay hold of important
suits in reference TO iron built ships BY the attraction ag
gregaon, the PARTICLES Of metals held together in what is
called solid state, although, phlosophcay speaking, there is
soidity about it. These particles Approximate with inf
mite nearness and yet touch another The cav
ties OF the metal filled with innumerabo globules of
and the application of heat expanding the air. drives the
alc particles asunder in proportion nearly TO the quantity Of
heat applied that if the heat be raised to very high tenn
peatue the hardest steel that manufactured may
under the action OF blow pipe be reduced to mpapabe
POWDER lighter than the atmospheric air. and will float in that
medium like the small dust Of the balance in the beams Of
summers
But immediate object is with iron only and to inquire
how far the general law Of expansion and contraction up
the matter in hand 1t may, however, DO observed that
the expansion of metals is not in proportion to
the movements OF heat applied The strength of cohesion il
weakened by every addition of heat and of consequence
less quantity is necessary less resistance and
therefore, the quantity added to high temperature would
occasion greater expansion than the quantity added TO
low temperature In view of this great and fundamental law
OF nature, sometimes fancy in the morning that hold the
mercy of Jehovah in my hand in the form of The
application Of heat only would at reduce to liquid
erform state in the very act of shaving would drop like
water at my feet, or dance away upon the breeze
few years ago DIR. Urc the author Of valuable dcton-
airy upon practical chemistry, then London, message
desiring to found him engaged in experimental
philosophy and perectng very ingenious steam valve, which
acted altogether upon the principle of expansion and
The oil the metallic connected the
valve by the heat Of the boiler opened the valve in proportion
to the degree of heat and the refrigeration of the heat again
closed it, SO that the quantity Of steam allowed to escape the
safety valve depended entirely upon the temperature of the
heat have hand of ascertainng exactly what
would be the expansion of ronbut ship 300 feet long,
for the addition of every 200 of heat do deem it
say in the present inquiry seeing the contraction under
equal degree of cold equal the expansion under similar
degree of heat easily perceive that every particle Of
matter in iron built ship in ceaseless motion The ship
is all alive seaserpent mighty SNAKE expanding and
its elastic folds at the bidding of unconquera
BILE and ever-actiye agent. 4a#s
On this point we have experience The merchant
ne affords but limited and unsatisfactory results The iron
steamships OF recently constructed in Great Britain have
not had time to demonstrate their properties and present
with experimental facts We thrown, therefore, upon the
of the mind and the necessity Of feeling to
the most important purposes which marine architecture can
be directed.
The objections already suggested in regard the COST du
raby, oater proo and expense Of repairs of the
lille iron steamship marine, common to all iron-buit ships
But with respect ships of there other objections,
arising from the peculiar of their employment shot
will penetrate the side of iron built ship well of
built of wood In that event. tho first thing that the
mind the difficulty of stopping the hole wooden plug
eectual in stopping hole made by shot penetrating the
side OF wooden ship but consequence OF the shagged
nature of oce made through iron plate is quite i'm
possible to exclude the water by wooden plug The OPEN
ing may be partially stopped, but in action time can be
allowed file away the ndentaons of the oce and fit it to
I'VE n nj and of such
admit sufficient water to food and endanger the ship
Whether the fragments of iron Sheet carried into the
ship by the force of the ball. would be destructive than
the spnters OF wooden plank, question which cannot
be determined by any evidence Of which but it
reasonable suppose that the difference would be just
that observable between iron and wooden ball. The
ron fragments detached from plate would be nothing less
than voey of shot sweeping through the ship and doing
more execution upon the than the shot ITSELF
Any thing like forcing in considerable portion Of the side
Of iron built ship would apprehend be certain destruc-
lion, adequate of repair would be had at
The ordinary Of repairing wooden built ship under
such circumstances would utterly fall and she be left
10 the mighty ngushing of waters that would enguph
her, In the present state OF marine architectural science
would seem, upon this brief view of the subject that the risk
too imminent the expense too large the durability Of the
ship too uncertain, and the advantages problematca
Justify departure from the established mode of constructing
steamships Of war in the United States
Since the foregoing remarks written, the steamer Br
annia has brought to our aid and in confirmation Of the
cluson to which had come most important inormaton
under the head OF Portsmouth, August 18th
Some remarkable results have been produced by the ex
permental shot practice from the Excellent the
Ruby, and it is expected the Admiralty will, in
luence stop the building Of and other for the pre-
sent The shots which hit the Ruby only penetrated the
side first struck but in passed through the
other side, carrying with it whole plates Of iron. In action
this would risk the total loss Of the vessel for heeng
to leeward, such body OF water must rush in that nothing
would prevent her sinking with all on board
"a representation Of this important circumstance, arising
from the trials has been made the Admiralty and
should further Experimental firing that serious risk will
be occasoncd TO iron vessels Of when exposed the
chance Of being struck by heavy shot, it is doubtful if the
Board will not abolish them of war;"
From the fact that the result of these experiments
ported to the Admiralty, may infer that they made
BY its orders and from the plain details pre-
sened to the public there does appear any ground to
doubt their correctness they do not far enough entire
y settle the question: they do go far enough settle the
mpocy OF building iron steamships of with weight Of
evidence SO preponderating against their utility
The silent process of change in the British Government has
going for years, and is acceeatng It's speed with
zach successive change We becoming repulcanaed
necessarily inconsistent