New-York tribune., 1904-09-18

flooring. The under side IS plastered as usual
About three feet from the ground an Iron graf
ing IS put in over the whole floor area, and upon
this the fire is built. Chimneys are provided az
the top and dampers for regulating the draught
At various points in the ceiling electric pyrOul-
eter couplers are introduced TO measure the
heat of the fire. These coUplers are made OF
platinum and rhOdiUm wires and are connected
back 70 a deIicately adjusted galvanometer in
small instrument house near by. which records
continuously the temperatures obtained with
wonderful accuracy. On top Of the building are
placed a number OF vertical scale rods. by which
any detection of the floor during the test may
be measured with a surveyors level mounted on
a nearby tower. Before the test the foor e
loaded with 100 pounds OF pig iron to the square
foot over the whole surface
The object Of the test as specified by the city
building code. is to ascertain the effect or a
furious fire against the ceiling for four hours
maintaining an average temperature OF LOO
degrees Fahrenheit for the whole time. AZ the
end Of that period the fire is quenched by ire
men with a hose connected to 4 regular city IRE
engine under standard pressure. The stream Is
directed against the red hot ceiling for five min
u'es, then the floor Is flooded. and again the
stream Is played On the ceiling for i've minutes
longer.
It would be difficult for person who had not
severity. The fire is furious. Flames pour our
OF the chinneys several feet high. and when
door is opened to add more fuel the flames burst
out with such fury that the hre1nen cannot au-
preach within several feet OF them without dan
ger OF getting burned Looking In at the IRE
when the doors are open. everything Is bright
red hot, sometimes nearly white for a temper
ature OF 1000 degrees Fahrenheit ts often re-
corded In such test Glass. silver and copper
would melt In It easily. and some grades or cast
Iron would begin to yield under the fierce attack
OF the higher temperature. The city fre1nen arc
unanimous In the opinion that no room IN any
building could burn with such heat for SO long.
because no ordinary room would have enough
infiammable material In It to maintain a IRE az
LOO degrees Fahrenheit for more than half an
hour.
However, 70 IS the combination Of water ard
IRE which Is the most severe ordeal the material
has TO withstand When the strong stream OS
cold water Is thrown with heavy force against
the red hot material the shock Is great and Il
there Is any tendency 70 failure II win cOms
then The sudden cooling contracts the metal
rods and beams. cracks the concrete or tile, and
the force OF the stream washes away every
ioosened particle. exposing new surfaces 70 ths
destructive agencies But the test IS not IN
ished; there remains fnal ordeal before tho
system can be approved The day following tns
fire. when everything has cooled. a load Of coo
pounds 70 the square foot is put on the roOr.
On 10 foot span test. this load amounts 20
% TONS and Is a mighty stress upon the already
more or less weakened construction II tho
noor stands this with middle detection OF not
moro than pa inches. 1t receives approval
Professor WOolSOn says the question is often
asked. Why impose test the severity or which
so far exceeds the probable usage a nOOr would
receive IN practicsT
HIS answer. and that Of tho Building Depart
ment. Is that IN case Ike this where fearful
consequences may result from a failure OF a
structure due 70 fire. nc test Is toe severe which