New Orleans Republican., 1873-02-25
Academy of Sciences

Last evening. before the New Orleans
Academy of Sciences, John Roy, Esq. de-
llvered . most interesting lecture upon the
explosive power Of water.
The lecturer said, substantially: The best
engineers differ upon the question whether
or not waite: can be 50 heated as TO explode.
Water divested of air and kept perfectly
still can be cooled down below the freezing
point without being frozen, and heated to
$500 without boiling, the condition in
stantly changing upon the slightest motion.
Steam may he hotter than water. A pOr-
tiOn OF tine river may freeze and the bal
ance not.
When boiler becomes incrustated either
with mud OF salt the incIustation is liable
to separate from the iron. The incrustation
being d non-cOnduutor, there would be a
great increase of heat. Two Instances of
explosion from the water rushing between
the incrNstatiOns and the iron and generat-
ing an elastic steam were compared also
one of "a boiler nearly full of water with
only four pounds OF steam pressure.
The danger Of an explosion Of water is
TO an explosion of steam as ,4bb, 500 Is 10
696. 30, or as III is to 1861
The reason why an explosion from water
is so dangerous compared with steam is be-
cause steam at 2l2o has 100 volumes ard
that of water from which it was made and
10000 of latent heat is stored up. while if
10000 OF heat be applied to water az 2l2O, it
will expand into 400 times its original
bulk.
An accumulation Of superheated steam IN
a boiler at rest, if brought into contact with
the hot water by some disturbing cause
tLhe heat and water being in quantities suf-
ticient), an explosion would be the result
Most explosions are attributed 10 pressure
suddenly generated.
Water contains qis, which upon ebulli-
ton escapes, and leaves the water inclined
to soIdify. Water thus deprived of air re-
uulres constant circulation, 10 prevent its
acquiring heat far beyond it- pressure,
which excess may amount 70 loo degrees
Fahrenheit.
A bucket of water thrown upon a mass
Of hot iron will cause an explosion.
Placing water between iron heated 20 a
white heat, and striking q blow upon il,
will cause the water to explode into steam.
Instances We're related OF cold water
being ;Urned into nearly empty heated
boilers, ara the instant the water came in
contact with the hot iron the boiler eX
pi0ded. The turning on of the water rem =
dies the low state OF the water. but i'll
creases the danger.
The lecturer illustrated how water might
blast into steam if its particles were sepa-
rated, hy the difficulty OF igniting solld
rOsin, and the ease with which it was burned
when powdered and thrown upon a flame.
The numerous instances quoted showed
how water il boiler. when the fires were
burning but the engine at rest, was in the
best possible condition to store up heat
that immediately upon one motion, one
stroke o. the pump. it flashes !pto steam
with explosive force. The pressure was il
stantlv raised from so to 100 atmOspheres,
from 735 to lE0 pounds upon q square
inch. A rope may bear a weight while at
rest, but # the weight be raised and let fall,
the rope may break. SO boiler may stand
u strain while at rest, but not the velocity
communicated TO the water by the motion
OF the boat il backing out.
Captain Roy's lecture was very interest
ing, and presented in an able manner to ar
attentive audience of ladies and gentlemen
:he affirmative Of the question whether or
not water may be SO heated as to explode.