Weekly hawk-eye and telegraph. [volume] (Burlington, Iowa) 1855-1857, 1856-02-27
From the Chicago Democratic Press
An Important Eiscovery-Expiosio il,
Steam boilers.


A Mr. Harshman, of Dayton, Ohio, processes
to have made some very important discoveries
in relation to the causes of steam explosions IN
boilers. from which he is enabled to dcduce
safe and certain means of preventing such
result Mr. IlarshmanS theory is, that water
contains A large amount of latent heat, which,
under some circumstances, is capable OF being
RAPIDLY and dangerously developed, and under
others, of being gradually freed without danger,
am! that 10 accomplish this 1t is necessary to es'
tabsh an electric or galvanic equilibrium in the
boiler That an iron boiler, covered in all but
its fire surface and flucs, with copper coating,
generates steam very rapidly, saving half the
tuel and cannot be exploded 1t may rupture
Inv oyer-pressure, and relieve itself by allowing
an escape of steam, but it cannot explode.
The correctness OF this theory, Mr. Harshman
saws he has Illustrated by repeated experiments,
in every one of which the result has been uni
tormly satisfactory Having satisfied himself on
this point, he is now taking measures to bring
his discovery and invention to the attention OF
the public, very justly believing that it will be
properly appreciated so soon as sufficient ev!-
dencc is furnished Of It's efficacy to prevent the
recurrence of a species of calamity highly de-
structive to life and property, \ few days since
Mr. Harshman instituted an experiment, TO test
the matter, at Cincinnati, in the presence OF sew
oral scientific gentlemen and practical engineers.
| Among those present was the editor OF the
Railroad Record, and we copy from that valua-
able journal the following account of it:
The experimental boiler employed WAS Sm III
cylinder without fiucs, twelve inches long and
eight inches in diameter The cylinder was
made OF iron % inches thick. and the ends
somewhat thicker. The seams were riveted and
so.dcrcd, and the safety valve fastened to the
boiler by solder. The furnace was of common
constructions, without return fuc. Tne boiler
was placed in Il strong frame of iron the ends
| being confined, one by u bar extending across
the end, and the other by square piece OF iron
/ ii, the centre One hal! the surface of the Cyl
in,lcr was exposed TO the action of the fire, the
other half was covered with copper. The ends
were also covered with copper. The safety valve
was confined by a long wire attached TO sprinT
balance The iucl employed was hickory wood
well dried The boiler being placed in such u
position that its explosion could do no damage,
the fire was lighted and The observers withdrew
10 !, distance 10 observe the pressure at the bal
auce, and watch the operation OF The eXper-
ulents In few moments, steam had risen 10
a hundred, IL hundred and fifty, and Two hun
,lred pounds, and in less than half an hoar, the
balance indicated pressure OF TWO hundred and
| sixtv pounds At this point, steam was observed
TO i. S C from underneath the copper sheetins.-
The safety valve was drawn tighter, aud The -hr,
issue. The safety valve was then ioosed anI
steam blown oil and the fire put out. On first
examination, the boiler seemed only 10 have
opened at the seam around tie front head, anc
nj the point where the safety valve WAS fastened
but subsequent careful inspection showed that
the iron had opened in lItle assures IN sercrs
places which were perfectly tight under any or
binary pressure. bur gave vent al the high pres
sure 10 which this experiment was carried. The
ends of the boiler had bulged oat to some eN
tent. and the impression OF the square nut a
one end was left very distinctly crushed into Tbs
copper Jacket. The day was clear and cold
with the wind blowing from the West.
This experiment Was repeated on Saturday Will
| the same rvSulr.
Now, according 10 al ordinary experience. tht
boiler should have burst with great force. ie
VIC are witness 10 the fact that il only rapturet
and gave vent 10 the steam as easily as S,iiei,
valve usually relieves an ordinary boilers---
Should subsequent experiment prove that Ar
Harshmans mode OF preventing explosion o
boilers is as effective IN hrge oaes rs IN those o
small diu,euslons il vii undoubtedly soon com,
INTO general u>r, aud thss gentlemans lialae vii
be handed down TO posFcriiy as ono OF the great
est beneiactoys OF the race.