The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1873-01-02
sUPNRHEATED STEAM.
Tho Cause of tina Fire at the Circus-0pinions
of Experts
MIR. Van Der Weyde on Fire Marshaa
McSrcdOn's Report.

MIR. Van Der Weydo on Fire Marshall
McSrcdon's Report.
To THE EDITOR OF HE HERALD:-
Our form OF government, preferable as IL ID
before other forms prevailing in the rest Of tha
world, has stiIl some Defects from which undoube-
eddy 1t will be purified in due time. One OF tho
most gIaring OF these detects Ia that men are oen
appointed to Oflces the duties OF which they can
not properly perform, simply for the want OF edu<
cationaI training OF the kind required for such
ONCE Fire Marshal Thomas McSpe6on is an Illus
traitor in point He publishes In your paper or
December 81 communication on superheatef
steam which ia q confession of ignoranc@
about the subject He asserts that IL
there is sufficient steam remaining in
the pipes after the fires have been banked
1t Is liable to turn into gas that makes
the pipes red hot and that this occurs "when
there Is absolutely not fire enough to make steam
from the water" This is simply an absurd assev-
ton, without any foundation whatsoever. When
there is not 1re enough to make steam from water
when the boiler Is under pressure or say sixty
pounds (which corresponds to 500 degrees Fahrcn-
heiD, how can the steam in the pipes become RED
hot (which corresponds to 900 degrees Fahren-
heit9 The highest steam pressure ever practt-
cally experimental with was $50 pounds to tho
square inch but no boiler, even the strongest in
use, can stand this. 1t requires special apparatus
on small scale to experiment safely with such
heat and pressure, and tins pressure corresponds
with only 500 degrees Fahrenheit--a temperature
which is several hundred degrees below red hest.
Only when there is no more water N the boiler IT,
would be possible for the furnace to heat the steam
to this a higher temperature without
bursting everything Superheated steam without
excessive pressure can only be made when an
active lively fire is In contact with tubes containing
steam without water. The Fire Marshal says
further "a pound Of steam will occupy 1900 times
the space of pound OF water" This Is msstate-
r,1ay.f n IN n
heit and as long there Is water left in the boiler
1T becomes less than this at higher temperatures
and pressures. out of contact with water steam
viii expand according to Narcotics law so thas
for every AGO degrees increase Of heat 1t will double
its volume therefore. at $40 degrees 1t will occupy
S,lOO, and at 900 degrees, the red heat, 1t
will occupy about 1900 times the space
of the water. Mr.. McSpedOn further says LESS
fire will heat that 1900 pounds of steam than the
pound of water" Here we have one pound OF
water expanded by heat into one pound OF steam
at 1900 times Its original volume, and Mr.. NC
Spedon calls IL q 900 pounds Of steam
That superheated steam may be very dangerous.
by making all woodwork in the neighb0rh0Od OF
the pipes as dry finder and very hot at the
same time, is evident; but that single furnace
with q banked-up fire not hot enough to make
steam from the water may cause the steam In the
pipes to become red hot IL danger which can
exist only In the Imagination OF people who labor
under the disadvantage of want OF Information
and OF sound judgment
Editor Of the MANUFACTURER and Builder.