Star.
London, England, 1817-07-17 00:00:00

REPO
REPO RTfroin du SELECT CUMMR2 EE on
STEAM BChiTS.

MINU FES OF EVIDENCE.
CRARIAIS HAMMY, EA. the Chair.

Mr. Buse Aoki, called in And examined.
Were you desired to go down to Norwich, to in-
quire into the cause of the explosion of the Steam-
Boat ?—.l went down as a volunteer.

Did you see the Steam-beat?—No, we did not; it
had been removed; we saw he boiler and pars of
the engine. . •
Of wh..m do you speak ?-erMr..Tisnothy Bramah
and Mr. Collinge accompanied me.
They were persons peefectly-konversant with en-
gines ?—Yes.
You saw the boiler and the engine ?.--T did.
In your opinion, what was the cause of that explo-
sion ?—The immediate cause had been the use of
steam of a very high expansive forte; the proximate
cause was the deficiency in the strengh of the end of
the boiler.
Of what was that boiler made, and what was its
construction ? It was made chidly of wrought iron,
but partly of cast iron.
What pan was wrought, and what part was cast
The boiler was cylindrical; the cylindrical part and
one end were wrought iron, and the other end was
cnst iron ; it appeared to me to have been previously
tif wrought iro is, but, for what reason I do nut know,
the wrought iron cod had been cut out, and a cast
iron end substituted in its place. .
Is it vur opinion, that any beiler so constructed
was unsafe ? As a high pressure boiler certainly.
What do you calf a high pressure ? I sht•uld call
from Whs. nem anis high pressure; the technical
phrase is applied to engines u here the motive force is
even by the expansive force of the steam.
Deilee what is the techeical distinction between
Vgli pressure and low pressure engines ? When
water is made eoil in the boiler, and confined so,
that the ste sm is not allowed to make its escape, it
continues to acquire expansive force as it receives
increase of hear; in the high pressure engine, the
piston of the mean: cylinder is forced down by the
expansive force of _the steam alone, against the re-
sistance of the atmosphere; when the piston has
arrived at the bettor" of the cylinder, a valve is
opened, and the steansiie altiowed. to escape into the
atmosphere, and the opt anon ii reversed; the piston
of the cylinder is made Co ascend by the same kind of
force. In the condensing engine, or the low pressure
engines, the steam having been once permitted to fill
the cylinder, a communication is then made between
the cylinder in which the piston works and the vessel
in which the steam is condensed : that is the distin-
guishing feature of the two engines. I will describe a
further difietence, which contingently arises out of the
vase of the two I that is, in the WO pressure engines the
engineer has it at his option to use what degree cf ex-
pensive force he pleases, to convert an engine adapted
for the power of five horses, or producing the power
of live horses, to that of ten horses, or to any other ex•
tent which he May think his materials capable of sus-
taining. In the luw pressure or condensing engines,
Be steam can never be advantageously employed
ove from Vi to Gibs. up-n a squat e inch.
Whatever power there is in what y ciu call a hig pres-
sore engine, the ptessere in that engine may increase
the power beyond what it is calculated for, and by
means of that may render it dangerous I—Certainly.
Is it your opinion, that a boiler could be made ut
proper materials, whit satety valves, and under proper
guard and direction, to make that high pressure pet-
teeny sale?--That would depend upon the quantity
of pressure to be used ; a safety valve might be carried
to 300, or to any assignable (Mee. I think that a high'
pressure engine may be made sale to a certain extent,
bet where they are left ad libitum they never can be
perfectly safe.
Do you mean to convey the idea, that it is impose'.
ble or difficult to adapt to a high pressure engine one
or two safety valves joined with a mercurial gauge,
acting at the same point of pressure, so as to make it
equally safe with that upoti 'any other construction
In answer to the first part .01 the question, relative to
the safety valve, I think I have answered that already;
that we can apply a safety valve to any degree of
pressure without any diffieelty, but that the safety of
the engine does not totally depend on the safety valve.
State upon what other circumstancesehe safety
of the engine depends ?—My idea of the difficulty of
obtaining a proper degree of strength at all times hi
the materials of which boilers may be made, arises
from the constant deterioration which those boilers
must be suffering from the action of the fire, and
from the various degrees of expansion and contrac-
tion operating on difierent parts of the boiler.
Is it then your opinion, that in high pressure en-
pines carried to that extent you mention, danger
would always operate ?—lt Would nut alwaysoperate,
but it would be extremely liable to accidents.
'ln fact you ,ourself would not chose to use a high
pressure engine, from the difficulty which exists,
either more or less ?—That is my opinion.
Have you made any calculation what would be
the force required to be used to propel a boat in na-
vigable rivers or canals ?—This does not admit of a
definitive answer. It depends entirely upon opinion,
how far one force would be dangerous and another
not; but if Steam Engines arc employed for the
purpok of propelling boats, that may be effected with
perfect safety by the low pressure ar condensing en-
gines, where the pressure raced not exceed Sibs.- to
the inch.

Of course that must depend upon the resistance to
be made, and the velocity required for the boat?—
Then I must wake choke of a more or less powerful
engine ;- I think it just to Jute to the Comniittee,
that there is an advantage to be derived front the use
of high pressure engines un board boats, which are
necessarily loaded differently at different times; this
different looting requires a different power in the
steam Engine, and' Ate high pressure engine is ca-
pable of having this addisioral power given to it with-
out any difficulty, whereas ia the low pressure engine:
they ate confined to the force first assignectto diem..
'What is the morainal of the low pressure engines
scarcely ever saw them beyond 6 lbs.
In high pressure engines there is a great saving of
fuel ?--Thete is in one a peculiar kind of those carted
high pressure engines; there is a considerable saving
of fuel in Wooll's engines ; but in the common ones,
I believe there is but little saving.
It therefore the engines were to be used where as.
saying of fuel would be of coolduable cookequcw;cl

high pressnre,erigines of a cemin construction would
be better adapted for that purpose thin low pressure
engines?—Where the saving wa sof much consequence.
If engines were to be used at sea, it would be of
considerable consequence. the engine and the fuel
being contained in a smaller compass ?—Woolt's en-
gine is not in a much smaller compass.
When you talk of the deterioration of the boiler.
bow long would a boiler properly constructed and
constantly used. be used with safety'—That is ex-
tremely uncertain ; I have known one boiler worn out
in six months, and another used for seven or 14 years.
The strength of cast iron boilers is extremely uncer-
tain s cast iron contracts in various degrees in diffe-
rent places, and therefore is liable to break.
You think that all cast iron boilers are dangerous?—
Certainly, when used for steam of high expansive force.
In your former answer, wh.:re you spoke of the ex-
treme difficulty of so regulating high pressure en-
gines as to ensure their satety, did you mean to speak
of those which had cast iron boilers. or of both cast
and wrought metal ones —Chiefly us to the cast iron.
It is more practicable to make a boiler of the mune-
able metals to resist a high pressure, as far as the te-
nacity of the metals is concerned ; but another diffi-
culty occurs which prevents the application of the
malleable metals to boilers for high pressure engines,
which is that of rendering the jiiiiiing of the plates
secure.

Do you mean then to say that wrought iron boilers
are not in frequent use to high pressure engines, in
point of fact ?-•I believe they are in much less fre-
quent use than the cast iron boilers, and in Wuoll's
engine they are scarcely used at all.
In not the cast iron boiler much cheaper than the
wrought ?.-I can scarcely tell that ; I should think
the cast iron would be cheaper, if made of equal
strength.
In case of the explosion of a cast or a wrought iron
boiler, which is attended with the greatest danger ?
Cast iron, unquestionably.
Why?—From the frangible nature of the metal.
What do you apprehend to be the common effect,
in case of the explosion of a cast iron boiler ?-•The
metal is broken into fragments, and driven off with
great violence in various directions.
What is the effect when a wrought iron boiler
gives way ?—Generally a rent ; but I have seen one
instance of a wrought iron boiler, where the whole
of the upper part was rent from the bottom, driven
through the house in which it was placed, and carried
to a considerable distance; I believe several yards.
Do you apprehend, that speaking generally, and
unless by some extraordinary circumstance, such as
the wilful shuttirg of the steam valve, there would
be any reason to apprehend such an effect as foil
have just now mentioned, to arise from the renting
of a wrought iron boiler?—No, I scarcely think it
possible.
Supposing the boiler to be made of wrought iron,
or copper riveted, and safety valves properly ad-
justed, with a mercurial gauge also adapted in its
diameter with due regard to the size of the boiler,
do you conceive that any reasonable apprehension
could anise resrecting the safety of a high pressure
engine ?—I think there might ; but with less appre-
hension as to the exteut of the destructive effect to
be produced.

You speak of less apprehension as to the destruc-
tive effect; have the goodness to explain that ?-011
account that in the malleable metals a simple rend-
ing generally takes place, it would seldom happen
that the upper part of the boiler would be torn tit.;
but in the cast iron the fragments would be scattered
about, and be more destiuctive.

Do you not know, that wrought iron boiler have
been used to all sorts of steam rosins for a conside-
rable time past ?—Yes.
Did you ever hear of any other than the single in-
stance that you hare mentioned, in which a wrought
iron boiler burst in such a manner?—No.

Do you know what was the occasion of the top be-
ing blown off in the instance you nlentioned ?—We
cannot tell what was the immediate :mon, but I
suspected it to ariaa front the shape of the boiler.
What was that shape ?—The bottom was of the
usual waggon shape boiler, convex inwards • the
concave part of she boiler was over the fire, and those
Who examined it with myself imagined that the en-1
gine keeper bad 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; I
never knew them make any other.
Mr. Woolf's boiler has been it: use neatly ten years?
I believe it has.
Did you ever hear of any accident happening to
their boiler ?—Yes, I have ; I heard it stated the
other day, by a brother-in-law of mine, Mr. Hall of
Dartford, that he had known two or three accidents,
bfil Without any fatal or injurious effects.
How many engines of the high pressure character
have been blown up ?—I. have heard of several.
Are there more than four ?—A great nary more,
if there are taken into the account those which have
exploded in America as well as here.
Do you emisider, low pressure boilers as safe from
explosion in all instances?—Used with no further
pressure than six pounds.
What renders them safe ?—Because they never em-
ploy steam of high expansive force in them.
What arc the means by which they are prevented
from using steam of high expansive twee in them ?
Because jt would be against the interest of the persons
using them to employ it.
Is there any other guard against the condensing
engine receiving such a charge of expansive steam as
will burst it, than the care of the engineet or the in•
retest of the owner ?—Certainly none ; because I have
ki.own instances where they have used in the same
engine both steam of a high expansive force, and
condensed it at the same time.
You havapever heard of low pressure boilers blow-
. ing up ?—Nos I have never known of any explosion
with injurious conseqeettees ; they give way repeat-
edly; but do no injury:
Is there any thing in low pressure boilers which may
depended uposi absolutely, for preventing the steam
acquiring an expansive force beyond what is intend-
ed regulated safety valves; mercurial gauges
or water gauges will at all times secure it.
Du those means of limiting the expansive force in
low pressure boiler} continue perfectly effie scious un-
der all autism:Luce* of misconstruction and ma-
nagemmt?-entat entirely depends upon the

strnctinn ; T have known safety valves fail in tliv.44
action from bad construction.

Can such or similar means be applied to high pres-
sure boilers '.Yes, certainly.
is not the feeding of low pressure boilers nsualy
done b 7 a column of seater; 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 '—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?
Unquestionably.
Are low pressure boilers employed in boats always,
or commonly fed by a column of water ?—I never
saw an instance of it.
If the mechanical means which are used to render
the low pressure boilers secure succeed, will not simi-
lar means render high pressure boilers secure ?—As
far as the expansive force is not permitted to arrive
beyond certain limits, so far it will afford security.
At what tspanaive force are low pressure boilers
safe, according to their usual construction ?—I have
seen very few boilers constructed for the purpose of
a low pressure engine, or a condensing engine that
wonld sustain a pressure of ten pounds, without oc-
casioning considerable leakage, or without forcing
the joints.
Are they not very often used with a force to render
them unsafe ?—l, never knew an instance of it.

Is not the explosion of them likely to do sniv-
chic( ?—Not under the pressure they are capable of
sustaining.
Not even if they are made of cast iron ?—Catainly.
Are they uniformly made of wrout,l►t iron ?-1;u ;
several of them are made of cast iron.

Are not the greater number of them made of cast
iron ?—No ; 1 :I pprebend not.
You cannot died state to the Committee bow many
instances of explosion you know of high pressure
boilers ?—No, I cannot. _ _

Are they more than in low pressure boilers ?—I
never heard of an explosion in the low pressure boiler
nt any consequence whatever, merely a givo.g way
of the plates or the wearing out of the bcolets ; not
such a bursting as can be called an explosion.
May not every instance of explosion of the high
pressure boilers with which you are acquainted, be
traced to bad construction, or palpable mismanage-
ment ?—1 have never examined many of them, and
therefore what they may be immediately traced to I
do not know-; but all the explosions I have heard of
have been occasioned by the use of steam of high ex.
pansive force ; the one I visited at Norwich certainly
arose from the detective construction of the boiler;
it was extremely ill constructed.
Was it not as well from the palpable mismanage-
ment of the engineer ?—That I do not know ; we
were told tb3t it was ; I have no doubt there had
been very great temerity and rashness.
Was not that high pressure boiler which blew up
in I.ondon the other day at a sugar-house, entirely
owing to the most palpable misconstruction ?—I saw
the boiler alter it had burst t and I certainly should
not have made a boiler in drat shape, to have with-
stood the pressure which it was intended to bear.
Was not that boiler made of a different thickness ;
one of it three-quarters of an inch thick, and
the other side two inches thick ?—Those are very
nearly the dimensions t but in addition to that, there
was a defect in the casting, what we csll a cold shut
in the iron.

Is not the use of high pressure steam completely
:n its infancy ?—Ctrtaiiily, its introduction to general
use is, of much later date than the low pressure
steam engines.
It is in tact to be considered as an invention of re-
cent date?—lt is.

Have Dot material improvements taken place in
the construction and ustt of high pressure boilers, in
consequence of the accidents which have happened
—I conceive Woolf's mode of constructing boilers
to be a considerable improvement; a very material
one I have likewi►e been told, though I have never
seen one, that Trevethick has invented; a method
of making boilers by increasing their length and de-
creasing their diameter, so as to render them capa-
ble of sustaining pressure to a much greater degree
than heretofore.

Tare more accidents occurred since the invention
of the high pressure boilers, than might have been
expected from the invention of any new system
whatever in the mechanical coastruction of engines ?
Perhaps not.
What expansive force of steam is generally em-
ployed in those high pressure engines ?—I fancy that
is very variable, from SO pounds to 120 upon the
square inch, or even perhaps higher than that.
Instances have been known in which a boiler has
been worked at 160 and ISO • have there not ?—I
have heard of such things, but I never knew of t arm.
What is the proof to which high pressure boilers
are generally exposed previous to their being used ?
—The most eligible proof they ought to be exposed
to, is by water.
To what pressure ?—I should think double Ilse
pressure to which they are intended afterwards to be
subjected.
What is the estimated Wee in your opinion which
would burst a high pressure boikr of the best con-
struction ?—That is very different, because it deprfids
upon the strength and construction of the materials;
I never entered into the calculation.

Have cot the greatest advantages been derived to
the mines and manufactures from the use of the high
pressure boilers ?—I believe inestimable advantages.
Have you any doubt that Cornwall has de:ived an
advantage which may be considered as incalculable
from them ?—None in the world.
Do yon think, from the few accidents which have
occurred in the use of them, there is any better ar„u-.
meet to be brought against the permitting them to.
be employed, than could be derived from the acci-
dents which hare arisen in the explosion of gun.
powder in the clearing passages in the mines ?—No,,
not as applied to the mines, certainly.
You have mentioned that security is afforded to
the engine by feeding the boiler by a column of
water; from what does that security arise ?—The
pressure from the steam in the boiler could never
rise to a force greater than that which would be
equal to the pressure of thec.luma of water; when-
ever it did arrive at that pressure, or beyond that
pressure, the water would be blown out and the
steam mould follow.

YO{. have smelt that in the Kelm vestels used

'open rivers, Wit ptee aution is not resot ts,l:
taw one, and it would be extremely ient.
For what reason ?-0.1 aced, .it

the water would be subject t 44 ; ii we 4ld
out of the pipe from the mra,ou et the
other inconveniences would arise, sesch as b: r
the pipe through the deck ut the vessel.
Do you apprehend, that a me-sari sl 2:t4ive
be exposed to the same inconvenrencvs
I dry; the altitude would be lesse.ied by evt,

assumed position of the vessel; that is, of a
placed vertically at first, should by t' e Avian

vetsell assume a diagonal or an
altitude of the column would he
consequent pressure ppm the steam Ipiteited.
Are you of opinion that there would ie
difficulty in Fu rding against such an inet‘,.relsi
as that I—Yes, I think there wool.!, rplly T.
ing i hut a well constructed sakity vilve

swtr all the purl), :es.
Are not the s.efety valves apo-,1 to the pi, 4
sure engines, even when the coliin:a of watts is
to supply the boiler ?—Most tricoeutly they rue; 1
bave seen some without.

Did you never hear ot 11e pressor- in a cerdeos.
ing engine being raised by m.artheive,:;..t t as tidy
as 19 or 20 lbs. per inch ?—ti.); l J • n.l rect.liect
that I ever met with SUCII a circuses.. have ,ar
doubt that it has taken place.
It such a circumstance my take ?lace a.orh a low.
pressure engine, do not you t;.inf:. ace, .f:
the general calculation of Ole streag.li t:i is r•
to feta,: the usual pres.a.re to wiecti t y
:-
ted, more.clanger would arise Ciao' in m s.
which could happen to a high pressut, r
a boiler properly adapted ?-Isltt, I • .
cording to the general construction at 1.A.,
bullets, they are so rivetted together to nulls! c
pressure they are intended to bear, eisil t..c.
I ways give indications of an incte..se ~f pe,s,•!te
`before I should apprehend any danger itooi
meanby the joints giving tray, and the ste,;;;) ;,
I cinq a passage through :Isem.
Do you tncan to apply that to the cast iron
ere
boilers.
The not ; to the wrought is an
per
The qaeition before put was meant to apply ta a
low pressure engine, fitted up with a cast it
As applied to ti,e cart iron holler, I sliostld say, roam
being constructed to be in a less degree os eyiaitLiva
force, an. explosion would vioner take
therefore would be less dangerous.
Less dangerous in comparison with what
a high pressure boiler.
Do yon mean to say, that an explosiol e! t!--1 cast
iron boiler of a low pressure engine st Lich s!;,101.1
burst by an improper degree ot press.”-:, wouhl 1;1
less dangerous than the tending of a wioo,.;!:: :Loa
boiler, occasioned by a much higher degt-c.. •:t p!es.
sure ?—I gave my answer as connects With the Ins-
ton question, With regard to the liability to danua
from low pressure boilers; I take for granted, th it
if a boiler is constructed to be applied to a lOW p-e,-
sure engine, that a commmsurate strength will be
applied to the materials of the boiler, and that in t!-.e
case of applying a boiler to a high pressure engine,
an adequate strength.must be used there to the press
sure intended; therefore if the low I ressure boiler by
any accident should be exploded, generally speata,:g,
boilers made of the malleable metals ruust be nasal
safer on an explosOn taking place, at least they are
not calculated to .da so much mischief as the cast iron
boilers.

Have you made any experiments, or are yeti ac.
quainted accurately with the effect of such as have
been made upon the different qttantities of t ',el con-
sumed in the high and the 19w pressure engines, in
proportion to the quantity of power produced
I have witnessed several experiments on Weolt
engines, where the object was to ascertain the com-
parative expenditure of coals or fuel in grinding crra
between his engines, and the :ow pressure or ccr.df.n.
sing engines, and the results were dec:dally iu
of Mr. Woolf's engines.
You cannot speak as to the high pressure engin,:
commonly in use apprehend there is no saving
of furl, or very little; there may be a little.
What was the saving of fuel by Woolf's engine, as
compared
•with the other ?-The average effect in one
case was the grinding eighteen bushels of what wits
one busht I of coals; the other average effect of Et,l-
- and Watt's engine, or the low pressure enzittes,
is the grinding of from ten to twelve bushels of wheat
with a bushel of coals. .

Do you know whether the power of the engines in
lifting water may fairly be reckoned at the same pro-
portionable difference ?—Yes ; I believe they may. I
do not speak from experiments ; but I have no dcu:.:
as to the effect; by the reports from Cornwall I a:n
led to suppose it may be much greater.
Ilave you seen any account of the explr,:ion
Steam• Engine on board a boat in America, withil.l
few weeks past ?—No ; I have not. I utticrst.l,..
there has been one.
From any information you received at Norwici:,
did you hear of any conduct of the manager of th.o
boat, which occasioned the explosion of the boiler ?
No; the information I did receive upon that subj'e.
was since we returned to Lnnclon.—( To le eeationaZ.)

- -•
DIED. ---
On the Utast:l4.lot, in his gmb year, very highly esteem...'.
William Wheeler, Lop of Winatifuld House, ureetenLite.
lie possessed extensive kuowledge, with a reculbr v gour rs.
energy of mind to the latest hour, united to a di:pniit,•in thr
most liberal, generous, and humane. By his lamented e. eat!' tie
County will experience the loss of one of iu oldest r•rdErritt..t
supporters of iudependenee.
Monday, at Bath, in the 54th year of his age, tote Ar.:r.!•;•
His I.ordshlp It succeeded in his titles and estate by hit • •
sots, James reerani Arundel

PRICE OF STOCKS YESTERDAY.
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COAL MARKE r, JULY 16.
Ships at Market. Sh's sold. Prices.
34* Newcastle St SG*. Gd. to 4:s.
3 Sunderland $ Vs. 6d. to t-s. ..
1 Stone Cost 1 GM (A.
1 Fore.t of Dean Coal t SGs. ed.
0 Wet Coal 0 o'.)c. 011.
1 Cinders 1 ^35.04.

HIGH WATk.I4 TO MORROW AT LONDON tuu:).,,
Morning - - •• 36 *Wu. after 4
Merlon n - . $6 ... 4
..

LetIDON- . a r a e d aad piebtiskycl by Levi:. Ss:; T,
Pim , I ernvie•isAr.