The Manitowoc tribune. [volume] (Manitowoc, Wis.) 1866-1878, 1868-08-20
THE SCIENTIFIC CONVENTION.
Boiler Explosions and their Causes---
A Neh System OF Prevention.

last the subject of boiler explosions wa
discussed We make the following ex
tract from the proceedings:
''Col. Wittlesey was next called to the
chair, and Prof Joseph Miller, Of New
York, was introduced to the audience as
the author Of a paper on steam boilers
ard the various causes assigned for then
explosions.
Drawings were placed upon the board,
of flask by which the experiments had
been made, which were to verify the pro
positions taken by the speaker. The
bottom of the flask was raised in the
centre for the purpose of concentrating
the heat in the centre of the water. The
flask was corked and partly filled with
water, and the heat being applied the
water gradually rose to 2l2 degrees
Fahrenheit, when it boiled. The pres
sure becoming sufficient to force out the
cork, the entire amount Of water in the
flask was drawn out with it.
At the next experiment a diaphragm
was placed within the flask, so that the
water which was first heated should rise
along the interior of the flask and be dis
placed by the cooler water on the other
side of the diaphragm On the appli-
cation Of sufficient heat to this flask to
drive out the Cork, the water Is not forced
out as in the ordinary flask The water
above the diaphragm o4ly will be thrown
out.
Another point gained by means of the
diaphragm Is, that an eddy Is formed
into which will fall all the sediment which
may be In the water, and, this sediment
being away from the fire, the heat does
not have the effect of hardening it.
The speaker next proceeded to notice
the valuable aid rendered by science IN
making discoveries for its amelioratlon Of
the condition Of mankind. The report
of Prof Badu ON the subject of steam
boilers was mentioned; but there still
remained much to learn before steam
boilers should become perfectly safe. He
regarded boiler EXPLOSIONS as comprised
under the following
l. Gradually Increasing pressure.
=. Sudden increase of pressure by the
exposure of heated surfaces.
3. IncruStatlGn.
f. Sudden contraction and expansion
of metal on a change Of temperature.
Prof Miller passed over the more mys-
ferrous so-called causes, such as electlc-
rlty, explosive gases, etc.
Prof. Miller proceeded to show how
steam was formed when the heat was
gradually applied to the boiler. When
the water Is heated 2iz Fahrenheit one
of two things iaay be done to cause
cbullition More heat must DC added.
or the atmospheric pressure may be
removed b. the air pump. Ii ire Is
aided, the steam in the steam space viii
increase the pressure upon the water,
which pressure retards ebuliIuon; tor no
ebullItIon can take place until the pres
sure of steam in the water exceeds the
pressure of steam il the steam space
Therefore much larger quantity of steam
must be contained III the water than in
the steam space When this Is the case,
if the safety-valve be suddenly opened,
the result will be the sudden release of
tile pressure, a violent rising of the water
under the safety valve, and a supply OF
steam from the body of the water If at
the same time there should be exposed
fues, or highly Gated metal with which
the steam can come into contact, no steam
boiler can Withstand the studded pressure.
\ rupture of any part OF boiler ought
to have the same effect as the action OF
the safety valve. The common cry is
that the safety valves are not Of sufficient
area TO allow the free escape Of steam,
whereas the rupture is generally amply
large, while the effects are the same.
When the boiler bursts all the water is
converted into steam. The immense
force exerted by the explosion of a boiler
Is so stupendous "a to cause many per
sons to accept the doctrine that they are
produced by electricity or the sudden
production of mysterious gases.
Prot. Miller related the following eX-
perimeat which be made 20 test the force
of the steam at the time Of explosion.
Selecting four boilers tayOra5iy located
we'll set, arranged w.;h proper damper,
and we'll covered, To retain the heat,
increased the steam to 100 pounds pei
square inch above the atmospheric pres
sure Steam was then admitted to
Carliss engine, that operated SIX machine:
which consumed 100 horse power. Aftel
running the engine one hour, the condi
ton was as follows: The pressure o
steam on three gauges was loo pounds
closing the hampers and drawing the fire
the engine was started At first higl
grade OF, expansion was used, gradual,
decreasing until at the end of forty-nin,
minutes the steam followed nearly til,
whole stroke Of the piston, or the entlu
cylinder full of steam was used duriu;
each stroke.
We then stopped two Of the machines
working tweny-seyen minutes, thel
throwing off two more machines anl
working nineteen minutes, when tn
engine was stopped with a boiler pres>ur,
OF twenty-five pounds and the water linz
between the second and lower gauge
cocks. This gives rs the power OF ID
horses for foxy nine minutes. loo TO
twenty-SeYen minutes, and % for nine
teen minutes When we now conslde
that in case of explosion the whole o
this force is eXerted IN a second OF time
we find that the power cxerted would bt
equa. to o0J,9Jy horse power, aa4, WAeI
We remember the loss of power in the
engine and the steam still remaining il
the boiler, 100000 horse power would
not overrule the actual results,-a powe
so stupendous the mind can scarcely con
celve its immensely When such is tn,
power contained in steam boiler, wha
need of looking for solution in the mys
ferrous working of the electric fluid. O
the production of explosive gases? Tn
power stored in the water is much NOR
IMAM SuiDt-tue " pi0ouSS ILG Most Oils
asterous results.
Incrultation is the worst enemy of tn
steam boiler Ii is poor conductor 0
beat. and, by preventing contact of tn
water with the boiler plates, the latte
become over heated, and consequent
rapidly destroyed, particularly as til
noncave form of our boilers causes tn
formation of sediment in the lowest poit