The Locomotive - Lighthouse Survival Blog

186 THE LOCOMOTIVE. [December,
The Deterioration of Rails.
Mr. T. D. Cook of Boston has kindly called our attention to an experiment
witnessed by him in the Government Building at the "World's Fair. A rail that had
been in use for some time was placed in the testing machine, and it was found to break
readily, without any material bending, when supported at the ends and loaded af the
center. The same rail was then placed in a furnace and reheated, after which it was
again tested. This time it was found to be much stronger; it bent through a consider-
able angle, and did not break. The rail was not worn to any great extent, but had a
tine, smooth polish on the top, from the action of the wheels. Mr. Cook suggests that
this experiment may throw some light on the breaking of rails while in use.
Mr. J. E. Howard, who has charge of the great testing machine at the Watertown
Arsenal, in commenting on this experiment in a letter to Mr. Cook, says: "The steel
rail in question was exhibited for the purpose of showing how a rail, originally tough,
would, after exposure to the wheel pressure, become devoid of toughness, and fracture
in a very brittle manner when bent with the head on the tension side ; and how the
metal might have its toughness restored by annealing: — in this manner showing that
loss of toughness was not, at least in this case, the result of incipient cracks forming in
the head, but that exhaustion in toughness is an independent feature in the deteriora-
tion of metals. The softer the rail, or the lower its elastic limit, the sooner will it yield
under the wheel pressure, and the sooner reach a state of brittleuess, so far as the metal
immediately at the top surface of the head is concerned. Rails which were planed off
^" on the head bent as well as the annealed sample. Of two samples of the rail which
you saw at the "World's Fair, when loaded at the middle on supports 30" apart, the one
which was loaded on the head sustained 99,800 lbs. total load, and bent 40 degrees
without rupture ; whereas the other piece, loaded on the base, thus bringing the head on
the tension side, fractured, without appreciable bending, under the load 63,900 lbs.
This behavior of rails which have yielded and the metal in the head flowed over the
sides under the wheel pressure, has been veritied in a number of instances. The rails
which are harder at the start appear to be affected in a similar manner, but in a less
marked degree. Yours respectfully,
J. E. Howard."
Professor John Tyndall.
A few days ago the world lost one of its foremost men of science, in the death of
Professor Tyndall. The Scientific American speaks of him as follows:
" On the evening of December 4th, Professor John T5'ndall died. The son of an
Irish policeman, a man whom he himself described as ' socially low, but mentally and
morally high,' he had before him the task of working his own way up in the world.
He was born August 21, 1820, in Leighlin Bridge, near Carlow, Ireland. He left school
at the age of nineteen, and joined the Irish Ordnance Survey. Here he may be said to
have begun his scientific career. In 1841 an ofiicial asked him how he employed his
leisure hours, and told him that with five hours a day at his disjiosal they ' should be
devoted to systematic study.' He added, ' Had
I when at your age had a friend to ad-
vise me as I now advise you, instead of being in a subordinate position I might have
been at the head of the survey.' Next morning, it is said, Tyndall was at his books at
five o'clock, and for twelve years followed the advice given him.
" He became dissatisfied with his slow progress, and in 1844 wished to emigrate to