The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1903-03-22
HOW STEEL GROWS TIRED
LAW OF BREAKAGE OF THIS METAL
NOT YET UNDERSTOOD.
Investigations and Experiments Now
Being Carried On-WOnderful
Machines in Use.

BOSTON. March H.-The law of break
ages is still unknown and unwritten. This
twentieth century-the age of machinery
Notwithstanding its wonderful structures,
Its ingenious inventions, and its brilliant
mechanical discoveries, still leaves unan-
swered the question Of how long a thing
will last and at what moment it will break
unexpectedly and under no unusual strain
and our most advanced mechanical Iabo-
ratories are still experimenting with struc-
tural materials, cropping for a satisfactory
conclusion.
freight car will pound along over few
hundred thousand miles of rough road with
apparent indifference; then, some time
when 1T Is moving at a very moderate
speed. mayhap on exceptionally even rails,
one of its hitherto sound steel axles breaks
short off and a disastrous train wreck is
the result. Similarly, a steamship fights
out many a gale, laboring against heavy
seas with her screw thrashing out of water.
and afterward in fine still weather, breaks
her propeller shaft as If were a pipe stem
and becomes helpless hulk upon the
ocean. A more striking instance is that of
the Brooklyn bridge, which, though un-
doubtedly built of originally sound materi-
ais. began to show signs of weakness, even
to the breaking of some of its members,
after certain number of years during
which certain number of cars and carts
had ratified over it. Evidently. If the laws
governing these apparently causeless break
ages could be discovered-and scientists
feel confident that laws do exist that de-
fine the endurance of all structural ma
terials-many lives would be saved and
many tons of useless material, which are
now added to the contractors burden
merely to secure a random factor of safe.
ty.' could be eliminated from construc-
ton.
Among the many truth-seekers the Mas
sachusetts Institute of Technology seems
to be in a fair way toward knowing the
answer" and as like as not will be the first
to come to definite conclusions upon the
matter. By what has already been found
out in different Investigations from time
TO time. all mechanical scientists agree
that the metals with which we build and
on which We impose such heavy strains.
have the same disadvantage of gradually
firing out and finally giving way as the
perishable muscles and sinews of our own
human bodies. Such is the common hypoth-
gin: but to how soon. and in what con-
ditions, and under how great a burden
this gradual firing out takes place-that is
what We must know in order to prevent
accidents.
BEGAN TWENTY YEARS AGO
The experiments at the Institute of Tech
nology in the strength of materials were
begun by Prof. Gaetano LAMA, who is now
In charge of the mechanical engineering
department. more than twenty years ago.
What was done before then was worked
out on a small scale. the theory being that
If piece OF wood two inches square
showed certain effects from given test.
another piece two feet square, for example.
would show similar effects in a proportion
ate degree. Professor LAMA. pointing out
that such differences were likely TO be in
correct on account of the varying quality