The Davenport daily gazette. [volume] (Davenport, Iowa) 1856-1869, 1856-02-18
IMPORTANT DISCOVERY

The Rsiiroad RIO q mentions that Mr..
Harshman, Of Dayton, Ohio, claims 70 have
msde some very important discoveries 10
relation a the causes Of steam explosion,
In boilers. aad By which he has been sn.
ahed to deduce safe and certsin means
preventing such explosions M. Harsh
m&n's theory Is that water cont.iGs large
amount oil istent heat, which under some
circumstances Is capable oi being rapidly
and dangerously developed, and under
others, of being gradually feed without
danger, -snd al! that Is necessary 10 at-
complss The latter result - " estsb!1sh an
iron baiIer covered in all bat is IRE surface
aud Cues with a copper coating, generates
steam very rapidly, saves hall the fuel and
cannot be exploded. II may rupture by
az over pressure, and 50 allow al escape 0f
steam. but il cannot explode.
The editor d the Record gives the follow
ing account OF an experiment which was
tried by Mr.. Harshman, at Cincinnati, in
presence Of several scientific gentemea and
practical engineers. u subsequent expert
IN ents show tina, similar results viii follow
~aen large boilers are Used, as followed in
the instance quoted, Dir. Harshman viii
have gained for himself high position
among the beneiactors OF mankind
The expesime n,sl boiler employed was
: small cylinder " thout hues, twelve inches
long and eight inches In diameter The
cylinder was maje OF ron 80 inches thick,
| and the ends somew hist lhieke, The seams
were riveted and so.dered, and he safety
valve fastened 10 the boiler by solder The
furnace was Of common construction, with
out return fiue The boiler was placed 10
strong frame OF iron, the ends being con.
| fined, one by bar extending across the
end, and the other by square piece of iron
| in the centre. One half the surface of the
( cylinder was exposed to the action OF the
| fire, the other half was covered with cop
| per. The ends were also covered with cop
! per. The safety valve was confined by
long wire attached to a spring baiaoce.-
TIE fuel employed was hickory wood well
dried. The boiler being placed ia s9eh a
position that its explosion could do no dam
age. the fire was lighted, anu The observers
Withdrew TO a distance to observe the press
ure at the balance, and watch the operation
OF the experiment. In few moments,
| steam had risen 10 u hundred, 4 hundred aud
flty, and two hundred pounda, and in less
than half an hour, the balance indjca Ted
pressure Of two hundred and sixty pounds.
AT this point, steam was observed 10 issue
from underneath the copper sheetlDg. The
safety valve was drawn tighter, and the TIRE
continued for ten minutes, steam continu-
ing TO issue The safety valve was then
iocSened, steam blown off and the fire put
cut. On first examination, the boiler seem
ed only to have opened at the seam around
the front head, and at the point where the
safety valve was fastened; but subsequent
careful inspection showed that the iron had
opened in little assures in several places
which were perfectly tight under any oidl-
nary pressure, but gave vent at the high
pres ,ure to which this experiment. vas car
ned The ends OF the boiler had bulged out
to some extent, and the impression of The
square nut at one end was left very distinctly
crushed into the copper jacket. The day
was clear and cold, with the wind blowing
from the west
This experiment was repeated on Satlr-
day with the same result. Now, according
to all ordinary experience. the boiler should
have burst with great force. Yet we are
witness to the fact that il only rupturad and
valve usually relieves an ordinary boiler"