The Sun.
London, England, 1817-07-26 00:00:00

STEAM BOATS,

Mr. I3RYAN DONKIN called in; and Examined.
Wvve you desired to go down to. Norwich, to
iitcove into the cause of the explosion of the
biedoi Boat ?—I went down as a volunteer. -•

Jiid yim see the steam boat ?—tio, we did not ; it bad been--
removed we saw the boiler and part of the engine.
Of whom do you speak ?—Mr. Timothy Drama,' - and Mr.
C,,!;.iige accompanied me.
They were persons perfectly conversant with engines ?;
Irt

Yon saW the boiler and the engine ?--I did.
In your opinion, what was the cause of that explosion ?-
-The 'immediate cause bad been the use of steam of a very
1,40 expansive force; the proximate cause was the deficiency
in the strength of the end of the boiler.
what was that, boiler•matte, and what was its construc-
tion ?•--It was made chiefly of wrought iron, but partly of

cast-hwin. -
What put si•as wrought, and what part was cast ?—The
boiler was cylindrical ; the cylindrical part and one end were
tv..ought iron, and the other end was cast iron; it appeared
to o.c to have been previously of wrought iron, but, for what
plum) do. not know, the wrought iron end had been cut

a.cast. iron end substituted in its place. •
Is it your o: ti inio, that any boiler so constructed was un-
safe. ?—As a high pressure boiler, certainly.
hat do you call a high pressure should call from 30
lbs. upwards high pressure ;-the technical phrase is applied
to engines where the motive force is given' by the expansive
force of the steam.

Define what, is the technical distinction between high pres-
suye• and kw pressure engines I—When water is made to
boil in the boiler, and confined so as the steam is not allowed
to nial-e its escape, it continues to acquire expansive force as
itaaevives increase of heat; in the high pressure engine, the
_piston of,thd steam cylinder is forced down by the expansive
fusee of the steam alone, :testiest the resistance of the atmos-
phere; when the piston has arrived at the bottom of the C)
limier, a valve is opened, and the steam is allowed to escape‘
into the ateressahere, and the operation is reversed ; the pis-
too of the cylinder is made to ascend by the same kind of
trace. In the condensing engine, or the low pressure'engints,
the steam staving been once permitted to fill the cylinder, a
communication is then made between the cylinder in which
the piston works awl the vessel in which the steam is con-
densed: that is the distinguishing feature of the two engines.
I will describe a further difference, which contingently arises
oat of the use of the two; that is, in the high pressure en-
gines the engineer has- it at his option to use what degree of
expansive force he pleases, -to convert an engine adapted for
tire power of five horses, or producing the power of five horses,
to that of ten horses, or to any other extent which be may
*hie!, his materials capable of sustaining.' In the low pees-
-sate or 'condensing engines, the steam can never be advan-
tageously employed above from two and a half to six lbs. upon
a.squese inch.
NV hateVer power there is in what you call a high pressure
engine, the pressure in that engine may increase the power
beyond what it is calculated for, and by means of that may
sender it dangerous I—Certainly.
Is it your opinion, that a boiler could be made of raper
Materials, with safety-valves, and under proper guard and
direction, to make that high pressure perfectly safe?--That
v.-puld depend upon the quantity of pressure to be used ; a
safety rake, aright be carried to three hundred, or to any as-
sigoatliS force. I think that a high pressure engine maybe
made safe to a certain extent, but where they are left ad
tune thc y kicser can be perfectly safe.
Du yon mean to convey.the idea, that it is impqssible or'
difficult to adapt to a high pressure engine one or two safety
velessionied with a mercurial gauge, acting at the same
puintof pleasure, so as to make it equally safe with that upon
any other construction 1-111 answer to the first part of the
spastimi, relative to the safety valve, I think I have answer-
ed that already ; that we can apply a safety valve to any de-
gree of pressure without any difficulty, but that the safety of
the engine does not totally depend upon the safety valve.
State open what other circumstances the safety of the
engine depends idea of the difficulty of obtaining a
proper degree ,of strength at all times in the materials of
which boilers may he made, arises from the' constant dete-
eiriration which those boilers must be suffering from the ac-
tion of the fire, and. from the various degrees of raven-
sion and coutractiurs operating an different parts of the
boiler.
Is it then your opinion, that in high pressure engines car-
vied to that extent you mention, that danger would always
operate would not always operate, but it would be ex-
treitisly liable to accidents.
lu fact, you yourself would not chose to use a Weds pressure
engine, from the difficulty which es.iels, either mare es kW •
—That is my opinion.
I.lare you rsade any calculation what wosithl be the foice
required to he used to propel a boat in navigable rivers, or
canals I—This does not admit of a definitive answer. It de-

pcmls entirely upon opinipn, how far one force would be
darq;erous and another not; but if steam engines are ern=
ployed for the .purpose of, propelling boats, that may he
ejlected with perfect safety by the low pressure or con-
tlensing engines, where the pressure need not exceed six lbs.
In the inch.

01 course that must depend upon the resistance to be
made, and the velocity required fur the boat ?—Theo I must
make choice of a mole or less powerful engine; I think it just
to state to the Committee, that there is an advantage to be
derived from the use of Isiah pressure engines on hoard boats,
which are necessarily loaded differently at different times;
this different I:nii:ig requires a different power in the steam
ettgine-, and the high pressure engine is capable of blaring this
;additional power given to it without any difficulty, whereas
in the low pressure. engines they are confined to the force first
assigned to them.

What is the maximum of the low pressure engines
se3reelyrer saw them beyond six lbs.

In liigb pressure engines there is a great saving of frn ?
There i> in one, a peculiar hind of t how called high pressure
engines; there is a considerable saving of fuel in. Woolf's en-
gines; hut in the common, ones., I. believe there is but little

If fikliefore the engines. were to be used where the saving
of fuel wonio be of considcrabte consequence, high pressure
engines of it certain. construction would be bettrr adapted for
t hat poepuse thaa, hue !pressure engines ?—Where the saving
was of machconsequence.
Af engines, were to, be used at sea, it would be of Consider-
able consequence, the engiqe and the fuel being contained
s-la Her compass ?-IVuolls engine is nut in a much
smar, r er,llll,asA. •
_ _ _

When you talk .of the deterioration of the boiler, how long
would a boiler, properly constructed and constantly used, be
used is its safety ?—=that is extresuiAy uticertain I hare
known one holler worn out in six Months, and another used
far sect aor festeteesi years ; the-strength-at cast iron boilers
t-M m .
is extresnely• um:ein ; cast iron cnnts'atts farhiliodegAles,
in different places, .and therefore is liable to
Yost think that all east iron boders ate dungenoas ?—Cer-
taissly, when used for steam of high expansive force.
In your former answer, where you spoke of the extreme
difficulty of so regulating high pressure engines as to insure
their safety, did you nas,ut. to streak of those which had cast
iron boilers, or of both (mg and wrought metal ones
Chiefly as t., the cast igran ; it is more practicable to make a
boiler of the malleable metals to resist a high pressure, as fin
as the tenacity of the metals is concerned ; but another difli-
enLy ~Cellr6, which prevenU the application,of the malleable
nititais to boilers for high pressure engines, which is that of
rendering the joining of the plates secure.
1):, you mean then to say, that wrought iron boilers are'not
iii rie.inent use to high pressure engines, ins point of fact ?—1
believe they ace in 'sieh less frequent use than the cast iron
boiSers ; and in Woolf's engine, they are scarcely used at all.
Is not the cast rear boiler much cheaper than the wrought
I s'a r scarcer tell that; I should think the cast iron would. be
e;o-asser, it made o, equal strength. •
.1.; case of the explosion of a east or a wrought iron boiler,
vs's. •is is ;Mended with the greatest danger I—Cast iron, un-
spo:ssiosis.tbly.
• W liy ?—From the frangible nature of the metal.
it do you apprehend. to be the common effect, in case of
of a case iron, boiler ?—The metal is broken
I's!, ir.senienti„ and driven oil with great violence in various
di t rctions.

Winit is the effect when a. wrought iron- boiler gives way ?
“eiaerai;y a cent; hut I have seen one instance of a wrought
wacre the whoie of the upper part was rent from
t;o• homwa, drAcui thruttgh the house in which it was placed,
ptvi cnn ied to a considerable distance; I believe several yards.
-ott apprehend, that speahing generally, and unless by
some eXtraord i nal y cirettmance, such as the wilful sbulting
mr :he straw valve, there would be arty reason to apprehend
mid; art effect as you have just now mentioned,. to arise from
time renting of a wrotnilit iron boiler !—No, I scared), think
it possible. _

imv.posing *.he boiler to,ite made of wrought iron, or copper
ri^fmted, anti safety valves, property adjusted, with a tue,,cu-
r., abio aitaited in. its diameter with due regard to the
boiler, do, you conceive that any reasonable ep-
i'• i..vuld arise respecting the safety of a high pressure

engine?--I think there might; bat with less,apprehension
as to the extent of the destructive effect to he produced.
You speak of less apprehension as to the deStructive effect;
have the goodliess to explain that ?-0n account that in the
malleable metals a simple rending generally takes place, it
would seldom happen that the upper part of the boiler would
be torn off ; but in the cast iron the fragments would be
scattered about, and be more destructive.
Do you not know, that wrought iron boilers have been
used to all sorts of, steam engines for a considerable time
_Oast ?—Yes. •
Did you veer bear of any other than the single instance
that you have mentioned, in which a wrdught iron boiler
burst in suck A manger ?—No.
Do you know what was the occasion of the top being blown
off in the instance you mentioned ?—Wesanaut tell what was
the imMediate• reason, butl I suspected it to arise from the
shape of the boiler.
What was that shape ?—The bottom was of the usual wag-
gon shape boiler, convex inwards ; the concave. part of the
boiler was over the fire, and those who examined it with my-
self imagined that the engine keeper had suffered the water
to be expended, or the whole of it nearly evaporated, leaving
a small portion of it in the lag of the boiler. •
The boilers invented by Mr. Simms and Mr. Woolf were all
of them cast iron:--I believe they were : tnever knew there
make any other.
Mr. 'Woolf's boiler has been in use nearly ten.years?—l
believe it has.
Did you ever .bear • of Anis accident happening to their
boiler ?—Yes, I have ; I beard it stated the other day by a
brother-in-law of mine, Mr.• Hall, of Dartford, that be
had known two or three
.accidents, but without any fatal or
injurious effectk.
How many engines of the high pressure character have
been blown up-?—I have heard of several.
Are there more than four ? —A great many more, if there
are taken into the account those which have exploded in
America as well as here.
Do you consider low pressure boilers as safe from explosion
in all instances?—Used with no further pressure tb4n six
punnets. •
What renders them safe ?—Because they never einplOy
steam of high expansive force in them.
NVltat are the means by which they are re •vcnted. from
using steam of high expansive force in them ?—Because it
would be against the interest of
-the persons 'using thew to
employ-it.
Is there any other guard against the condensing engine re-
ceiving such a charge of-expansive steam as will burst it, than
the care of the engineer or the interest of the owner?—Cer-
tainly none; because I have known instances where- they
have Used in the engine both steam of a high expansive force,
and condensed it at the same tine.
You have never heard of low pressure boilers blowing up ?
No ; I have never known of any explosion wilb injurious
consequences ; they give way repeatedly, but do no injury.
Is there any thing in low pressure boilers which may be de-
pended upon absolutely, for preventing the steam acquiring
an expansive force beyond what is intruded ?—Well regulat-
ed safety valves; mercurial guages or water giuges will at all
times-secure it.
• Do these means of limiting the expansive force in low pres-
sure boilers continue perfectly efficaciolis under all circum-
stances of misconstruction and mismanagement ?—That en-•I
tirely depends upon the construction ; I have knOwu safety
valves fail in their action from bad construction.
Can such or similar means be applied to high pressine
boilers ?—Yes, certainly.
Is not the feeding of- low pressure boilers nsually done by
a-column of water ; -and is not this column the great reason
of their safety ?—That is one reason, but they ought to have
a safety valve besides. .
Is it not the principal reason of their safety I—lt is the
most secure one.
If the feeding column of water be taken away, is not the
security left to depend upon the safety valve ?—Unques-
tionably.
Are low pressure boilers employed its boats always or com-
monly fed by a column of water ?—I never saw an instauce of
it.

If the mechanical means'whicb are used to render the low
pressure boilers secure succeed, will not similar meaus.remler
-high pressure boilers secure ?—As far as the expansive force
is not permitted to arrive beyond certain limits, solar it will
afford security.
At what expansive force are low' pressure boilers safe ac-
cording to their usual coustruction-?-1 have'Seen very few
boilers constructed for the purpose of a low pressure engine,
or a condensing engine, that would sustain a preSsure of ten
pounds, without occasioning considerable leakage, or withuat
forcing the joints.
Are they not very often used with a force to render therit
unsafe ?—I never knew an instance of it.
Is not the explosion of them likely to do mischief ?—Not
under the pressure they are capable of sustaining.
Not even if they are made of cast iron ?—Certainly.
AFC they uniformly made of wrought iron 1,--No; several
of them are made of cast iron.

Are not the greater number of them made of cast iron ?
No; I apprehend not.
You cannot then state to the Committee howinarry i,ostances
of explosion you knOw of high pressure boilers ?—No, I owl-
not.

Are they more than in low pressure boilers ?—I never heard
of an explosion in- the. low pressure boiler of any conse-
quence whatever, merely a giving way of the plates or the
wearing out of the boilers; not such a bursting as can bat
called an explosion. _ _ _

May not everfinstance of explosion of the high pressure
boilers with which you are acquainted, be traced to bad con-
struction, or palpable mismana;ement ?—1 have never exa-
mined many of them, and therefore what they may be imme-
diately traced to I do not know; but all the explosiens I have
heard of have been occasioned by the use of steam of high
expansive force; the one I visited at Norwich certainly arose
from the defective construction of the boiler : it was extreme
ly iil coustructed.•
_ _

Was it not as well from the palpable mismanagement of
the engineer'--That Ido not linbw; • we were toll that it
was.; I have-no doubt there had been very great temerity and
rashness.

Was not that high pressure boiler which blew up in lon,.
don the ether day at • : sugar-house, entirely owing to the
most palpable misconstruction ?—Lsaw the boiler after it
had' burst ; and I certainly should not have made a boiler in
that shape, to have withstood the pressure which it was in-
tended to bear.

Wits not that boiler made of a different thickness ; one side
of-it three-quartvrs of an inch: thick, and the other two
inches thick.?--Those are eery nearly the dimensions ; but iii
addition to that, there was a defect in the casting, what we
call a cold shut in the iron.

, .
Is not the use of nigh presstire steam completely in its in-
fancy?—Certainly, its introduction to general use is of mucii
later date than the low pressure steam engines.
It is in. fact to be considered as an invention ' of recent
date ?—lt is.

Have not material improvements taken place in the con-
struction and use of high pressure boilers, in consequence of
the accidents which have happriitd?--I conceive Woolf il
mode of constructing boilers to be arousitterableimprol
ment; a very material one I have likewise been told,: t.bongis
I hare nee,/ seen one, that Trerethick has inveWel; a Inc-
thod of making boilers by increacing their Itligth and de-
creasing tkeir diameter, sty- ae- to render then) Capable of
sustaittims. pressure to z", much greater degree thwt hkretof
tore.

Have more accidents occurred since the invention of the
high pressure boilers, than might have been expected from
the iinvention of any new system whatever in the rkiechanicat
construction of engines ?—Perhaps not..
What expansive force 'of steam is generally employed in
those high pressure engines ?-1 fancy that is very vari-441e,
from 30 pounds to 120 upou the square inch, or even perba.pi
higher than that.
Instances have been known in which a boiler has been
worked at 160 and 180; hare -there not ?—I have heard of
suck things, but I never knew of thesis.

What is the proof to which high pressure boilers are g-
nerally exposed previous to their being used ?—The most
eligible proof they ought to be exposed to, is by \valet%
TO what pressure ?—I should think double the pressute to
which they are intended afterwards to be sunjectett.
What is the estimated force in your opinion, which would
burst a high pressure boiler of the best construction
is very ditkrent, because it depends upon the strength and
construction of the materials; I never entered into the calcu-
lation.

Have not the greatest advantages been derived to the mines
and manufactures front the use of the high pt essure boilers?
—I believe inestimable advantages.
- Have you tiny doubt that Cornwall has. derived an adtan•
tage which may be considered as incalculable (pout them ?
None in the world.

Do you think, from the few accidents which hare oceurrxd
lathe use of them, t here is any better argument to be brought
against the permitting them to he employed, than could be
derived from the accidents which have arisen in the explosion
of gunpowder in. the clearing passages in. the mines
not as, applied to the mines, certainly.
. • -
You have mentioned that security is atfOrded, to. theengine
by fording the boiler L a. coltinin. of•water ;. from what does
that security arise he pressure, from the steam in the
boiler could never rise to w force grezn,s than that wiiich.

would be equal to the pressure of the column of i•ater ; when-
ever it did arrive at that pressure, or beyond that pressure,
the water would be blown out and the steam would follow..

You have stated, thitt in the steam vessels used upon rivers,
this precaution is not resorted to ?—I never saw one, and it
would be. extremely inconvenient.
For what reason ?--Qn account of the undulations the
water would be subject. to : it would be thrown out of the
pipe froM. the motion of the vessel, and other inconveniences
would arise, such as bringing the pipe through the deck of
the vessel.

Do you apprehend, that a mercurial gauge would be
ex-
posed to the same inconvenieitces ?—Certainly, I do ;' the alti-
tude would be lessened by every new assumed position of the
ve ; that is, if a tube placed vertically at first, should by
the action' of the vessel assume a diagonal or an oblique po-
sition, the altitude of the column would be lessened, and its
consequent pressure upon the steam lessened.
Are you of opinion that there would be much difficulty in
goat ding against such an inconvenience as that ?—Yes, I
think there would; generally speaking; but a well-construct-
ed safety valve would answer all the purposes.
Are nut the safety valves applied to the low pressure en-
gines, even when the column of water is mused to, supply
the boiler ?—Most frequently they are; I . hare seen souse
without.

Did you never hear of the pressure in a condensing engulf
being raised by mismanagement as high as 19 or 20 pounds,
per ineh ?—No ; I do not recollect that I ever met with
such a circumstance; have no doubt that it has taken
ph ce..
If such a circumstance may take place with a ton ,pressure
.engine, do hot you think, that according to the general cal=
culation of the strength of their boilers to resist the usual
pressure 'to which they are subjected, more danger would
arise than in almost any case which could happen to a high
pressure engine with a boiler properly adapted ?--No, de-
cidedly not; according to the general construction of low
pressure boilers, they are so riretted together to with.tand
the•low pressure they are intended to.hear, and they always
give indications of au increase of pressure long before I
should apprehend any danger from it; .1 mean by the joints
giving way, and the steam forcing a passage through them.
Do you mean to apply that to the cast iron boileri ?—NO,
certainly not; to the wrought iron or copper boilers.
The question before put was meant to apply to a low pres-
sure engine, fitted up with a cast iron boiler ?—As applied
to the cast iron boiler, I should say, that being constructed
to bear a less degree of expansive force, an explosion would
sooner take place, and therefore would be less dangerous

Less dangerous in comparison with what ?—With a 'higilt
pressure boiler.
, Do you mean to say, that an explosion of the cast iron
boiler of a low pressure engine which should be burst by art
improper degree of pressure, would be less dangerous than
the rending of a wrought iron boiler, occasioned by a ankh
higher (levee of pressure ? gave my answer as connected
with the former questifm, with regard to the liability to danger
from low pressure boilers; I take for granted, that if a boiler
is Constructed tube applied to a tow pressure engine, that
commensurate strength will he applied to the materials of
the boiler; and that in the case of applying a boiler to a high
preSsure engine, an adequate strength must be used there to
the pressure intended; therefore, if the low pressure boiler
by any accident should be exploded, generally speaking,
boilers made of the malleable metals must be much safer on
an explosion taking place, at least they are not calculated to
tiq so much mischief as the cast iron boilers.

Have you made any experiments, or are you acquainted ac-
curately wish the effect of such as have been made upon the
different quantities of fuel' consumed in the high and low pres-
sure engines, in proportion to the quantity of power pro-
duced ?-1 hare witnessed several experiments on Woolf's'
engines, where the object was to ascertain the comparative
expenditure of coals or fuel in grinding corn between his en-
gines and the low pressure or condensing engines, and the
results were decidedly in favour of Mr. Woolf 's engines.
You cannot. speak as to the high preSsure cuginei commonly
in use ?—l'apprehend there is no saving of fuel, or very
there may be a little.

What was the saving of fuel by Woolf's engine„as cont.;
pared with the others ?—The average effect in one case was
the grinding eighteen bushels of wheat with one bushel of
coals; the other average effect of I3olton•and Watt's engine,
or the low pressure engineS, is the grinding of from ten to
twelve bushels of wheat with a bushel of coals.

Do von know whether the power of the engines in lifting
water may fairly be reckoned at the same proportionable dif-
ference ?—Yes ; I believe they may. Ido not speak from ex-
periments; but I have no doubt as to the effect; by the re-
pirrts from Cornwall, I am led to suppose- is may. be much.
greater.
• Hate you seen any account of the explosion of the steam
engine on board a boat in America, within a few weeks past? 1
—No ; I have 17.4)t. I understand there has been one.

. -
From any information you teceired at Norwich, did you
hear of any comitiet of the manager of that boat, wich ocea•.
sioned the explosion of the boiler ?—No ; the information I
did receive upon that subjcer vrXs since we returned to. LOn.dOn

LAW INTELLIGENCE.

COURT OF CHANCERY, JULY Q.

The business of the Court was of no public im-
portance, his Lordship having been occupied the
whole of the day iu hearing a bankrupt petition
of no general interest.

MASTER IN CHANCERY.
'Mr.-CouareNEY, M. P. has been, it is said, ap-
pointed one of the Masters of Chancery, in the
rootn Of ROBERT STEELE, Esq. deceased.

SHERIFFS' COURT-COUNTY OF THE CITY OF

DUBLIN.

GEORGE EVANS BRUCE, Esq. and MARY his Wye,_
Plaintifs--,TnomAs GRADY, Esq. Defendroit.

This-was an action ,brought by the plaintiffs,
against the defendant, as author and pablisher of
a libel upon the plaintiff Mary, contained in the
celebrated Poem called the " Nosa-gay," publish-
ed by the defendant. It appears that this action
was instituted by the plaintiffs against the de-
fendant, in the vacation preceding the last Easter
Term, at the time when the defendant was setting,
out upon al- tour to the Continent—that no ap-
varance was entered by the defendant, and judg-
ment being had by default, a writ of inquiry was
,sped before the Sheriffs of the .city of Dublin.,
without the knowledge of the defendant, or any
person Oft his behalf; and that 30001. damages,
were obtained thereupon, in consequenee•oft such'
default. That defendant, upon his having obtained.
information thereof, laid the facts of the case, and
the eircuinstances attending it, before the Court
of Common Pleas, when their Lordships were
unanimously pleased to set aside the said verdict,
with liberty to issue a new inquiry, to be sped
before the said. Sheriffs,, and a- most respectable
Jury, specially summoned for the purpose.
Mr. GOOLD, on behalf of the plaintiffs, stated
their case, in a speech of considerable 'length,
which, for eloquence, learning, and style, has not
been excelled on any-occasion.; and, after proof
of the publication and authorship of the poem,
and its circulation through Great Britain and
Ireland,, the plaintiffs, closed their case—when,
Mr. Botrrott on behalf of the defendant, ad-
dressed the Court and the Jury, in an animated
and pointed speech, wherein-he-adverted to a for-
mer action, -brought by the
_plaintiff; George,
against the defendant, upon almost the entire of
the poem alludedto, and the defence made thereto
by ,the defendant, before a Special Jury of the
county of Limerick, where the parties reside, and
the nature :and amount of the damages _assessed
by them ; when, after a most able charge given
to the Jury by the Sheriff's Assessor, Counsellor
Unhand, the Jury, after a few minntesdelibera-
tloll, found a verdict for the plaintiff of Gcl. ttt.
Biases,. with ad. costs,