Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1851-08-16
TO THE EDITORS.
THE PRINCIPAL CAUSE OF THE EXPLOSION
1890 OF STEAM-BOII Frs

THE PRINCIPAL CAUSE OF THE EXPLOSION
s35sss OF STEAM-BOlLERS.
10 Pspns Dgeser which Is an air-ght boiler used for
dssovng bones, &C., may be heated to 1000 without
ebuon, but If the be then removed oIe-6h of the
water rushss out in the form Of sesm and the rest Instantly
coos down to 2i20 Consequently the has carried of
from each OF the remaining our-6hs of the 400
2l2-lsso Of heat, that is, 1873 r lss - s40o; and
this great quantity Of heat has been rendered latent for it,
at the moment OF escape Thermometer Is held close the
ori6ee, il rises only to 2lao but Immediately after, when
the steam condenses water yields this calorc again
@ though the naked hand may be held close to the oce
It viii be tremendously scalded at little distance.
Hence Il is manifest that must receive at least 94Oo
Of caore 70 convert II into Of the temperature Of 1920
provided the quantity above stated as escaping from the d.
gester At 40Oo be correct.
Water converted into stesm Of the temperature Of 1922
expands 70 1888 times It's ordinary volume and if this steam
Be then heated over quantity Of water closely confined
more and more Of the win be converted into sea end
elasticity Of this steam, and the consequent explosive pres
sure against the inside the containing vessel will Of
advance pcr passu with the dimnuon OF the water on
which the steam floats because increasing quantity Of
steam will be generated till the quantity Of csonc Cor heat
rendered laten) 940x54,700o or perhaps to
040 8x5 5,2040 and oil the has been converted
into steam This stesm at that moment will have attained
it, maximum elasticity, and pressure Of little less than
two thousand pounds upon every square inch with which
| Is in contact.
That this the true story Of the elastic force Of steam sp
pears from the fact stated BY Dr. Thomson, that when steam
heated 1892 without the presence Of water
times and the temperature Of 5000
il volume would much exceed that of the water from
which generated and then it certainly would not sup
the counter pressure Of the atmosphere upon the outside
| Of the boiler
Mr.. Perkins confined quantity Of steam in an alright
vessel and heated it to l4000 and by gradually injecting
water. and gradually setting free the heat ihs. had been
rendered latent or 10 other words, by cooling the stesm
be conses and consequently generating additional
quantity, the elasticity and consequent bursting pressure
gradually augmented to hundred atmosphere,
1880 pounds upon every square ncb without any addition
Of heat
If the above reasoning be correct does not seem to be
difficult to account for those dreadful caasrophies on our
steamboats, which have engaged the scientific world for years.
as generally supposed We generally read The boat
had Just cast Off wAen," &c. Now suppose boat stops
when the remen have just filed the furnace and urged the
fire tois intensity ito put her under good Roadway
in the START But the valves closed no more steam is
condGsed the pump being idle the reservoir is of course
neglected and the boilers receive no more water. The
damr being insufficient check the FIRE completely,
ca the fuel be stone-coa the the boiler rapid
y changed into steam, which decreases in volume its
centaon augments till the internal pressure Of the
longa countebaances the external pressure Of the
sphee and the boilers crusheds collapse Or the
concentration Of the steam does not proceed to this extent
and The boat STARTS then, the passing through the
hinder, the apump brings into the reservoir, from which
the water is rapidly poured into the boilers and the
heated steam already there uniting with the water raises the
float opens the ,oGter regulator and supplies water in abun-
Dance which, uniting with the Of the highly
steam the boilers, increases its elasticity somewhat in
the experiment Of Mr. Perkins, and violent explosion is the
nevape consequence for the safetyvave contived
for letting off gadua surplus is totally inefficient to guard
agsinshe enormous quantity suddenly generated Ihave
never ZEN heard this chain of reasoning any where il
il ney, or you think it worthy, you may publish il.
respectfully, yours, &c. II. R. sCHETTERLY.
HwKLL, MIcHIeAs, JULr !, 1851.
-Lavoisie i, 10000, Rumford at lo4os0, while
j WIT makes e40o.