The Madisonian. [volume] (Washington City [i.e. Washington, D.C.]) 1837-1845, 1838-09-19
THE MADISONIAN.
From ths National Gassiis,
BOILER IRON.


Whether regarded as branch Of our rapidly increas-
ing manufactures or as means OF securing the saie
action Of tho steam engine boiler iron equally merits
careful attention.
Il 10 already a heavy item in the manufactures Of
Pennsylvania, and tho increase Of steam machinery
seems destined greatly to augment the demand for its
production Our anthracite il may be hoped, will even
tuay play distinguished part this business, well
a. 10 steam navigation Experiments are in progress
both the Lchgh and the Schuylki to test the prac
tcabity Of manufacturing iron with that fuel aided by
the hot blast
The great diversity in the properties Of boiler iron
produced in different manufactures, and by different
processes, should be sufficient put the makers Of
steam engines on their guard respecting the character oil
that which they employ.
city on the strength Of materials for steam boilers the
amount Of published information on the tenacity and
other properties of sheet iron was very small
In the Parliamentary examinations OF 1877 we lind
Mr. John Steel tesying that cast wrought iron Is
at its greatest strength when it is at 800 degrees Of
heat" which he thought however, had never been ar
rived at yet BY steam" No experiments were cited to
prove the OF his statement the business
OF his opinion II possible that steam at 5000 OF tenn
perature 4t afmospheres) had been much used in
England in 1917, though long before applied at tenn
perature Of $500 in the United States The only trials
TO ascertain the effect Of heat the tenacity OF iron
previous to those undertaken in Philadelphia, are be-
lieved to be three made At Clchy in France, by
Cagnard Latour. Their experiments had reference,
not to steam boilers, but to ollgas retorts which at
Clichy were made of sheet iron
They found the strength Of good bar iron to be 81 900
pounds to the square inch, when tried at ordinary tenn
perature. but only ii 075 pounds when raised dbl
red heat losing nearly 56hs Of its tenacy,by the tenn
perature in question They obtained for the strength of
the best quality Of sheet iron, $500 pounds, aud for
rolled copper 5000 lbs per square inch The small
number of experiments, the absence OF all means Tor
measuring the temperature and tho fact that trials to
certain the weakening effect OF beat were made, not
plate, but hammered bar iron, sufficiently Indicate
that the investigation Cchy affords satisfactory
solution of questions relating TO the steam boiler.
The result Of the experiment just Cited has been &C.
casionay referred in this country without, however,
stating the authority which rests, the circum
stances under which the trials were made.
Before the publication of the report OF experiments
made at the Frankln Institute, newspaper state
ments had been promulgated, by persons unconnected
with the research, from which, it supposed de-
rived the information communicated TO the committee
which examined the Of the explosion board the
Steamboat New England. One Of the witnesses on
that OCCASION testified that iron increases in strength by
additions Of temperature to $50 degrees He cited
experiments to prove the position, nor did he allege
that he had himself made any Investigations to that
effect.
With view to a comparison between bar and boiler
iron and between the American and European expert
ments several trials Of forged iron, made and
account Of the results may precede Of the
character of the material appropriate to steam boilers
The relative as well the absolute tenacities OF the
several kinds Of bar iron submitted trial in
the following synopsis in which the origin of each kind
OF iron, the weight in pounds required to break it, and
the number Of experiments made upon each at ordinary
temperature exhibited, together with the compare
tive value Of each kind Of iron referred to the best Rus
sian hammered bar, assumed as standard