The Express.
London, England, 1847-09-22 00:00:00

THE LATE FATAL EXPLOSION

ON THE RIVER.

ADJOURNED INQUEST.— (Sixth Sitting). Mr.
Bedford at to-day, shortly after ten o'clock, to proceed with
this important inquiry. The last adjournment that took
place, it will be remembered, to allow time for the engineers
appointed by government (Mr. Lloyd and Mr. Hughes) to
complete their experiments, and prepare their report. The
first witness war,
Edward Portwine, Catherhteartreef, Pimlico, writer on

.
engineering, who &mad: I am not a practical man. I have
visited all these boats, including the Cricket, and found
them working at a higher pressure than ought to be put on
them. I judged from the mercury, which was as high as 37,
and from what the engineer said. I told him it was en int.
proper pressure fur this kind of boiler, which was tot three
feet in diameter.
By Mr. Le Breton : The boat was moored at London-
bridge when I noticed the mercury at 36. It was in January.
I din not notice the valves.

By the Jury : I never heard of such a thing as working
such engines with a pressure of 35. It is not usual to have
a greater pressure than 27i. There might be strength enough
for 40, but I should not like to sit upon the boiler.
By Mr. James : Locomotive engines work at from 3.5 to
80. All depends on whether boilers are constructed for high
or low pressure. The Cricket engine was for low pressure,
and condensing. This information I te.d from the engineers
on board. I have not examined the engines.
The Coroner intimated that this evidence was of no value,
and that it was no use persevering in the cross.ex iminatiou ;
and sere rat of the jury expressed • similar opinion.
Mr. Thomas Lloyd I reside in the Admiralty depart-
ment, Somerset-house, and am chief engineer and inspector
of machinery in the navy. I have examined the machinery of
the Cricket steam-boat. I first examined it on the second Mon-
day after the accident. I have had a few drawings prepared
as illustrations. (These Mr. Lloyd laid before the jury.) One
is a plan of the •et gel as she appeared ; another a plan of the
boiler; another a drawing of the safety-valve and weight, the
full size; another of the soring.balance, with its valve, also
full size ; 11110a1Pr showing the boilers its they or i:ivally were,
which I had from Mr. Joyce. I also produce some speci-
mens of the iron composing the Cricket's boiler, and
some which I had cut out for the purpose of expe-
rimenting on at Woolwich. With regard to the en-
gines themselves, I don't think many observations
necessary. They are high-pressure engines, on the
principle well known as Wolte's . Each engine has two cy-
linders ; in one the steam is used at a high pressure, and,
instead of perking into the open air, as in an ordinary high-
pressure engine, it passes into the second and larger cylin-
der, whence it passes into the condenser, and is there
condensed in the ordinary way. The object of this arrange-
ment is of course the saving of fuel, by effecting • saving of
steam, nod, therefore, of fuel. So far as I saw, the materials
and workmanship of the engines were good. As compared
with high-pressure engines, there is nothing objectionable in
these engines, in point of danger—nothing but the ordinary
construction. There were attached to the engines two
pumps for feeding the boilers ; another pump was worked
by an auxiliary engine, which was commonly called the
" donkey ;" and there was a fourth pump, to be
worked by the hand, for feeding the boilers.
These appeared to be all that was necessary. There
were two boilers, consisting of an external cylinder,
five feet in diameter, haring • hemispherical end at the
back, and the front being composed of a fiat plate. To this
fiat plate are fixed a cylinder, forming the furnace, and all
the small tubes through which the products of combustion
pass. The internal part of the boiler, consisting of the fur-
nace, the fire-boa, and the small tubes, were secured to the
shell by the rivetting round the circumference of the front
plate. and by two stays, one fixed between the end of the
fire-box and the end of the boiler, and the other fixed ob-
liquely between the top of the front and the upper part of
the shell. A steel dome was also rivetted to the top of each
boiler, on each of which were two safety-valves, pressed
down by levers, one lever haring • weight at its
end, and the other a spring-balance—Salter's balance.
The thickness of the tube-plates was 3-4ths of an inch;
of the front•plates, those on the top and bottom of the tube-
plates, 3.Bths of an inch ; the shell 3.Bths of an inch. The
front of the boiler consisted of three plates, one of these
being the tube-plate, and the others the plates above
described. The steam-dome is 546ths of an inch; the
angle-iron round the front of the boiler is 3 inches by one half.
All the other angle-iron is 2i by 3-Bths of an inch. The
rivets in the boiler are 3 4ths of an inch is diameter, and the
rivets in the steam-dome rather smaller. That theludes the
rivets in the shell; all the rivets of any importance are
3-Iths of an inch. Assuming each boiler to be of the power
of 16 horses, the total heating surface in the boiler is
14 8-10ths square feet per horse power. The area of
the fire-grate is 55-100ths of a foot per horse
power. There is nothing objectionable in these proportions,
I either in the amount of area of fire.grate or of heating sur-
face. The quantity of water in the boiler up to the middle
gauge-cock is about 3 5.10 cubic feet per horse purer ; and
the steam-room about If feet per horse power; that is in-
eluding the dome and the other part of the boiler. I have a
great more dimensions here, but I don't think it necessary to
mention them. I have calculated the pressure up( n the
safety-valves, supposing the weight to be at the extremity of
the lever, at very nearly 661hs. per square inch. Taking the
spring-balance an it was when I saw it, the pressure per
square inch when the valve was just about to open, would be
401bs. per square inch ; but if the valve were as wide open as
it could be, this spring-balance would produce a pressure of
about liOlbs. per square inch. Both valves are lever
valves ; one is pulled down at the end by this spring-
balance, the steel-yard, the other is operated on by • weight.
As the lever of the spring-balance rises, by the valve open-
ing, the pressure on the valve increases, and rises to 170Iba.
at the highest. One pound on the spring-balance produces
a pressure on the valve of nearly two pounds. Those valves
operate jointly on the boiler, both serving to empty it of
steam; but they operate separately from each other. I
think if they bad all been properly In operation, the steam
could not have accumulated in the boiler to any dangerous
extent—that is, supposing them not to have been overloaded.
I do not approve, certainly, of the arrangement of this
spring-balance valve; it is objectionable because, when
the valve has been raised to such a hei;ht as to
relieve the boiler considerably, the pressure brought
upon it is very greatly increased, the power of
the lever being nearly as ten to one. This is not the
usual way in which spring-balances are used, as far as I
know. I think the principle wrong on account of the
pressure being increased when the valve opens. I
think it wrong in principle to put a spring-balanse
at the end of • long lever. I altogether object to
valves being in the power of tho engineer to load at his
pleasure, especially the high-pressure ones; but it is only
fair to say that this is too commonly the case. It can
scarcely he a matter of opinion that this is wrong in prin-
ciple. Nothing in the weighted valves called for observa-
tion, except that if it had not been intended to work these
boilers at a pressure of &Gibs. to the square inch, such a
weight as that ought never to have been put upon
the lever. The same remark applies to the spring-
balance valve, because it can be screwed down or up to any
extent. The weight being upon the lever was objectionable,
as it would be an indication to the engineer that he might
use it in any way he thought fit, so as to obtain that pres-
sure, namely, 661bs. As to the construction of the boiler,
I may say that, in my opinion, it is dangerous to be used as
a high-pressure boiler. The whole of the pressure of the
steam within the boiler is brought, either directly or indi-
' rectly upon this fiat plate in the front. I find, when the
pressure of steam is 661hs. on the square inch, the direct
pressure on this plate is 83 tons, which I withstood entirely
I by the stiffness of the plate itself, with the small addition of
the two stays before mentioned. I do not believe that 661bs.
on the inch would have buret the boiler at present, though
it might have done when the boiler was somewhat
older. The objections which naturally lie against a
flat plate of this kind are these • In the first place, you can-
not calculate what it ought to bear - the pressure on the
inside of it tends to produce three different effects. First,
there is a strain brought upon it at right angles to the sur-
face, and, if the plate were perfectly rigid, there would be no
other effect; this not being the case, an enormous pressure is
brought upon it in its own plane, which may be illustrated by
considering the effect produced on a musical string when
pressed sideways, the force brought to bear upon it length-
ways being far greater than when stretched in that direction.
A third action is produced by the bending of the plate, the
outer circumference remaining nearly in the same plane, and
the inner part being considerably bulged. From the best ex-
amination I can give the subject, I have come to the conclu-
sion that the strength of this front plate, aided by the
two very imperfect stays which were put in the boiler, was
not suMeient to bear, for a length of timo—that is, during
the usual time a boiler may be supposed to last—a pressure
of steam of 6016. on the square inch. At present it would
bear it, no doubt; there is no question of that. If any
person wished to tie down the weighted valves he would,
most likely, prevent the spring-Wawa valves from
working, whirl he might sadly de by putting in • plum of
wood. I bays calculated, in a rough way, what would be
the effect of keeping all the valves tied for five minutes.

Supposing no steam were permitted to escape. and the plea-
sure was 611ib., at the end of five minutes it would increase
to more than 901 b. ' • and, at the end of ten minutes, be
between 130 Th. and 1401 b.; in a quarter of an hour,
at lout 1801 b". That is, supposing no steam es-
caped, that the fires were burning briskly, and the
botler in full operation. I cannot conceive four valves
getting out of order, or sticking, at the same time. One
valve, supposing the other three to be fast, would not
relieve the boiler of steam as fast as the steam was generated,
looking at the size of the steam-pipe. If two were in opera-
tion, one of Salter's, and one of the others, they ought to
relieve the boiler ; bat the area of the steam valve
is larger than that of the waste ateamtpipe, which
is not a good arrangement. The area of the form's' is
nearly five inches, of the latter, only 2 7-10 inches. If the
two weight-valves were tied, and the epring balances free,
I think a dangerous pressure would he brought upon the
boiler. After making an examination of the boiler, I
thought it proper to test the goodness of the materiels; and
I took pieces of the plates of the boiler which had been rent
by the explosion. These plates, as I said before, are f of en
inch in thickness. I cut !strips of 2 inches in width from them,
both with and against the grain, and tore them asunder by a
tuachlne for that purpose at Woolwich. Four of the pieces
produced are four of the strips of the boiler ; two torn with,
and two against the grain •, the other four are pieces of good
metal from Woolwich, with which I compared the former.
The former are, in fact, part of the plates which were rent
in the explosion. Withont troubling you with
the details of the experiments, I may mention
that the average tensile force per square inch of
these plates was 17 tons, that of plates of the same
thickness, of the best kind, which I tned at the aame time,
was 211 tons. Specimens of those are also produced. They
are low moor plates, of the lame thickness, but of a very
superior quality. The plates of the Cricket are very much
laminated or ahelly, not only in one part, but all that
I maw. This is awing to the bad quality of the metal.
It will happen some times in plates of the best quality,
but it is very much to be avoided. This piece ex-
hibits the fracture actually mad, by the explosion, the ap-
pumice of which proves it to have been bad iron—that is,
for the purpose to which it was applied, to a high-pre sure
boiler, and considering that it wee employed in the part which
was most likely to break. I tried also some common Staf-
fordshire plates, at Woolwich, and found their strength nearly
the same as tbst of the Cricket's plates. They bore 161 tons
on the average, which is low. I do nut conaider the
workmanship of the boiler to have been such as
it ought to have been in a boiler of this kind.
The rivets generally did nut fill the holes, and
They were generally not sufficiently long to make a good
rivet. The boiler does not appear to be seriously deterioratea
by wear, except at the lower part of the front, and possibly
the bottom too may be so ; but I do not attribute the ex-
plosion to that. The part which exploded was the whole of
the front, which was torn Cut bodily. Of course the part
was weaker than when quite new, but not materially so.
The experrnents I have mentioned are not tests of the pres-
sure of steam on the plates ; all we can say is, that a pressure
of 60;b. ought not to be permanently put upon it, say
for three years. From these experiment., and ano-
ther of bending the iron, I should nay that the metal
was not ;such as ought to have been employed.
It was good common metal, suck as is usually
employed in the boilers of the navy for part• where there is
no great strain ; but not such as ought to have been put in
the front of the boiler. The plate was torn where it was
weakest, and in the stronger part it was torn from its fasten-
ing. By consent of Mr. Smith, Mr. Joyce:and other parties
interested, who have afforded me every facility, I have made
experiments on the unexploded boiler. I brought
on it a pressure of 1361 be. to the square inch, showing
that the other must have been subjected to a very severe
pressure. In the unexploded boiler both the stays were sepa-
rated, and a part of the angle-iron, which unites the front
to the shell of the boiler, was cracked. Upon this boiler I
brought a pressure of water of 1361 b. on the square inch, and
then the boiler leaked to so great an extent that a greater
preesurecould not be obtained. My opinion iethat the pressure
of steam which caused the explosion could not have been lees
than 13016. to the square inch. That is, of course, a matter of
opinion ; but it is the conclusion to which I have come. I
should not have expected it to burst with a less pressure;
but, as I said before, it is utterly impossible to calculate it.
You can calculate perfectly well what the shell of the boiler
ought to bear. I should say it was not less than
13616. ; how much more, I cannot trey. I do not
believe there is any reason to suppose that there
was any deficiency of water .in the boiler. It is
called a tubular boiler, from the eireunistatice of a num-
ber of small tubes being introduced, for the purpose of ab-
sorbing the heat. We consider them rather a safe boiler.
The business of one or two of these tubes is a matter of no
importance. The tubes seemed to be all perfectly good.
Two or three of them were bent, but the cgue of that was
very evident from striking against the inside. My great ob-
jection to the boiler is its form, the front being flat, without
proper staying; and, in a far less degree, the quality of the
materials and the workmanship. There can be no doubt as to
the cause of the explosion--namely, the improper increase of
the pressure of the steam, shortly before and at the time of
the explosion. If the pressure was gradually increased,
from say 6011 x., to 130Ibs. or 14011 w in the course of ten mi-
nutes, that would be enough to account for it—certainly, if the
pressure rose to 150Ib. ; but that is a mere matter of opinion.
That the boiler had never before been subject to such an ex-
treme pressure is evident from the fact that the other boiler
leaked considerably at almost no pressure at all; and I consider
that it had been rendered thus leaky by the extreme pres.
sure on the day of the explosion. The boilers are connected
in the water spaces and in the upper part of the steam,
so that the pressure on both would be the same
at the same time. If only one valve was in operation
on one boiler, the pres.ure of steam on both would be the
same ; and even if both valves of one boiler were secured so
as not te work. To show the great pressure brought on the
unexploded boiler, I may mention that the fiat plate in front
was bulged to the extent of 11 inches before I commenced
my experiments. After it had been subjected to the water-
pressure of 1361 b on the square inch, the bulging of that plate
increased to 2-16 inches; and the lower front plate of the
boiler began to break exactly like the one that was broken
in the exploded boiler. Had all the four valves been at
liberty, it appears to me impossible that the pressure of
steam could have so increased as to cause the explosion.
Had both the balance-valves been open, I think they
would hardly have saved it ; they might have de-
ferred the time, and prolonged it from 10 to perhaps
20 minute'. I think the valves must have been closed
or open only to a smell extent, when the explo-
sien occurred. (Here Mr. Lloyd exhibited • plan of the
vessel and boiler, and explained to the jury how he conceived
the expiation to have occurred.) When the front began to
bulge, the stays would be the first to go ; the plate would
thee bulge more and more, and the moment the separation
took place the inside of the boiler would be projected in one
direction, and the shell in another. The former was driven
against the engine, which resisted it, and to this the people
in the fore part of the vessel owed their safety.
The shell of the boiler was carried in the other
direction, and tore away every thing in the stern
part of the vessel. Assuming the actual gross pressure at
180 tons, and adding • ton and a-half for the weight of the
'hell, it would give a force ahundred times greater than that
of gravity, which will account for tho enormous power
exerted in a comparatively short space of time. In the
exploded boiler, I was not able to examine the spriag-
balance, as it was blown to pieces. In the unexploded
boiler, the balance appeared to be in a good state : it was
correct.

By Mr. Chambers The object of the spring to the valves
is not to prevent it opening too widely, but merely as a
substitute for the weight iu a more convenient form. I ob-
ject to it on account of its increasing the resistance so con-
siderably. I do not disapprove of spring valves, but of the
manner in which they were placed, at thejestremityofa lever
the proportion of whom arms is ten to one, so that a pres-
sure of one pound on the spring-balance would be equal to
two on the lever. That objection has nothing to do
with the principle of the thing; Mr. halter's 'prin.
' balances are very excellent things. I object to the
engineer having any control over the valves. They may
always be raised, but not pulled down. I object :o the en-
gineer having the power of increasing the resistance. That
is the course adopted in the royal navy, but not in locomo-
tive*. It has been used in the navy from the time there has
been a ate* navy, and has been without exception for
many years. The engineer has the power of pushing up the
valve, but not pulling it down, so as to increase the pressure.
There is a valve ends weight, but he cannot increase the
pressure. In the unexploded boiler, the balance-valve
erred to be adjusted to about 401 b. that is,
40 h. when the valve was shut, the pressure increasing
with the opening. For anything I can tell, it
might be set fest, and not act at all ; the instrument, taken
by itself, may be quite correct, and yet the lever may have
been prevented rising. There was nothing to indicate that
it had been wedged, or stopped from acting; if it had there
would have been no mark left. Had both the balance-valves
been in a fit state to act et the time of the explosion, a
longer time would have been necessary to get up the
steam to the bursting preenre. I am hardly prepared
to say whether they would have been opened so as
to let off the steam sufficiently quick. I very much doubt
whether they would have done so, both on account of tke
valves themselves and the smallness of the waste steam-
pipe, by which it passed Into the chimney. Had only one of
these valves been open, there is no question it would have
produced a very great noise ; every one near must have heard
it. Even had the pressure been 401 b., or 20Th., any
one near the funnel must have heard the steam going up.
There ought Smile two valves to each boiler ; but I should
have preferreertwo weighted valves to the spring.balance
ones. The mercury-gunge is intended as a guide to the
engineer, as to the pressure of steam. It is liable to get out
of order, either from the admission of water or air, by
which its proper action is prevented. There is nothing
else beyond that and the safety-valves by which
the engineer can judge the pressure of the steam.
The experiments of te unexploded boiler was made with a
gradul preen». The lower plate began to giro at about
120 lbs. and the boiler began to leak a good deal. Had the
jreware been applied suddenly, and come with • lamp off s
erk, the force is incalculably greater. I do ad Moo
now there could have been any form of ispeli
)1,114
explosion, as the steam cannot be got up ikt
I sin at a loss to eons/ire how a prOIOSII eedd lasi
been applied eo suddenly as to create the loosed how*, try
which we describe a force acting suddenly, like a blow, or

a cannon ball. Both the stays in the unexploded boiler had
been 'operated before I began my experiments. This might
bare been caused either by sudden or gradual force. The
giving way of the stay would produce a slight mo-
,: mentum in its sticking against the front-plate; and
there would also be the momentum arising from the
bulging out of the front plate itself; but I donee attach much
Importance to that ; it cannot be made matter of calculation.
The breaking of the stay would be like giving a blow to the
front plate, but it if impoesille to calculate its force. I will
not say it would be so sm ill as not to be taken into account.
The sudden strain, in addition to the gradual drain, would,
of bourse, be greater, The stays themselves were strong'
enough; the fastenings had given way. 1 here were four
boles in the hock stay for pins, and one of them had been
tarn out. My calculation of the increase of pressure from
60Ib. to 901 b. in five minutes, supposing all escape cut
off, is merely a rough calculation. I should be very
sorry to verify it by experiment. Knowing the quantity of li
water in the boiler, and knowing how much a boiler of that
bind will convert into steam, and taking the quantity of I
heat required to raise the steam, and allowing for the elasti-
city produced, I have come to the conclusion above stated.
It supposes that the fires were burning briskly, the blast on,
and everything to be done for creating steam most rapidly;
but'if anything was out of order it would not be correct. I
did net put it forward as mathematically correct. In the
exploded boiler the tubes are not burst. I did net notice
that any of them bad been plugged up. The leaking'
of the tubes would not much affect the (generation
of steam ; they would only let out the remaining water.
Still, if anything was the matter with the tubes, or if they
wire not sufficiently long, the heatingpower might be dimin-
imbed ; but it would be matter fur inquiry whether other cir- '
cumetunces would not counterbalance this. In this boiler

the tuba were...tolerablygood. My calculation of the steam
rising in a quarter of an hour to 1801 h. is made in the same
way. At such a pressure the halanenvalve would have
been raised ; and when the preemies was removed, it would
go back to its original place. If it did not let off steam fast
enough, the pressure would still increase till it became dan-
gerous. The escape of strain in this way would have made •
great noise. In such a state of things, the engineer or
stoker, if be understood his business, would instantly have
drawn the fires.

Mr. Chamber Are engineers employed in the navy who
understand these things thoroughly.
Mr. Lloyd: I know very few pi runs who do understand
them thoroughly ; but no engineer is employed in the navy
who has not undergone such an examination as may be
determined on to be necessary. If au engineer understands
the effects produced on and by his engine, I should coil him
an educated man. It is all a question of degree. You must
get the hest man you can, by riving a high rate of wages.
A man who knows the construction of the engine, and who
has assisted in making it, if lie be a man of common-
sense, would make a very good engine driver; but if be was
sot so, he might be worse than one who did not understand
so much, and had less confidence.
By Mr. James : At the precise time of the explosion, I
think the occident could not have happened had all the
valves been in operation. I should have arrived at that con-
clusion, without the evidence I have heard; but
it is fortified by that evidence, also by the evidence that
no steam was blowing off at the time. This is
not necessarily so ; because if the steam was not up
to the working pressure, none would blow off. Under the
other circumstances, it would corroborate my opinion that
the valves had, either by accident or design, been prevented
from working; as would the fact, had it been established,
that the guage rose suddenly from 40 to 80 This would
hove settled the business. II do not think a pressure of 661bs.
on the square inch would have burst the boiler at that time.
This was the maximum pressure which the weight on the
valve would have allowed, if placed at the extreme end of the
lever, or a little more, allowing for the steam overcoming
the resistance. The weights are so adjusted too often insteann
vessels. In the royal navy there are no levers the weights
hang underneath. I have no objection to the engineer ad-
justing the pressure, if he does it with the knowledge of those
interested ; but he ought not to be allowed to do it while the
vessel is under weigh. In the other case, where there are
no levers, he can go in and alter the weight; but there it is
as a reared against him. The spring-balance produced (one
handed to the witness by Mr. James) is a better than the
one in the Cricket, as it is made to act at 40. It would be a
guide to the engineer if he could see it ; but, assuming
him to be reckless about his own life and that of others,
he might stop the working of the balance-valves as well
ss the other. In the navy there are no high-pressure
engines, nor any of what are called Wolfee. In locomotive
engines, high-pressure is used, necessarily se Ido not
object to it as a matter of principle. The high-pressure
principle is applied to stationary engines, for working
steam-hammers and so on. The average pressure used in the
navy is about 25 1t,,. to the inch. In my experiments on
111se unexploded boiler, I found it had already bulged II
inches, and afterwards 6-16 of an inch. It was not a very
severe teat for • high-pressure boiler. Some allowance is
due for corrosion, and for wear ; but the maker of the boiler
ought to make these allowances. It bad been strained
considerably on the day of the explosion ; but no great
allowance need be made for that, as, in any case, before the
boiler could have been burst, that amount of strain must
have been endured. The stay* had been bunt; but this
also must base taken place, in any case, before the boiler
exploded. I compared it with Low Moor iron, which is the
best, and is very little used for commercial purposes; but it
ought to be used for the strongest part of these boilers. I
think the strength ought to be ten times the average work-
ing pressure likely to be required ; in other words, that a
boiler ought not to be worked at • prensure more than one-
tenth of the ultimate strength of the boiler. lam told these
b)ilers bad been proved before they were put in the vessel ;
bat the test would be more as to the tension than the
strength. lam told the high-pressure railway engines work
at from 801bs. to 100 lbs. pressure. It is well known they are
constructed in the best possible way. The Low Moor iron
ought always to be used for some parts of boilers, or some
metal equal to it. The highest specimen of the Low Moor
iron bore a strain of 221 tons on the square inch. I have
made high pressure boilers of that metal for the govern-
ment, nod I have no doubt whatever that it is used
for some commercial purposes. Almost all tubular boilers
have flat plates at the end of the tubes,; but this boiler
varied materially from the ordinary construction, so as to
be defective. If obliged to use a flat plate like this. I should
take care to stay it so that the stays would resist the entire
pressure. If the valves were kept tied down so as to give a
pressure much above 661be.,it would causean unnatural strain
upon the boiler more than the maker had calculated on, and
it would be weakened in consequence, except such parts as
were strong enough to resist it. Unless it wu three or four
times as strong it would necessarily be weakened ; and, as-
suming this great pressure to have been used, some allowance
ought to be made to the maker of the boiler for that. I
made no experiment on the dome of the boiler; but it with-
stood the pressure of 1361b5. along with the others.
It would resist that, or three times as much ;
it is not the vulnerable part of the boiler. My
calculations as to the rapidly increasing pressure
of steam with the valves closed, are founded on well•known
principles, and the calculations of others. I would on no
account undertake to construct a boiler to be worked with
closed salves ; still less would I undertake to work such a
one. I have not yet made any report to the board of trade.
One stay is at the back, the other at the front of the boiler ;
both inside, of course. The pressure which burst the boiler
would act on all parts alike ; and when the stays separated,
the front plate would bulge out. This would give a slight
momentum, but I do not think it is worth talking about.
The strain upon the boilers, arising from the long-continued
practice of tying down the salves, would weaken them in
proportion to their quality. The guage, if graduated up to
180 or 200, ought to have accurately indicated any thing
which this boiler has borne. Ido not know whether any of
the crew had had access to the spring-balance before I saw
it ;it may have been in other hands. I saw no cord round
any of the levers.
By the Coroner: At the time of the explosion the pres-
sure must have been at least 130 or 140. My reason for
Doming to that conclusion is, that this pressure disabled the
remaining boiler.
By Mr. M'lntyre : The accident would not have occurred
had all the valves been opened. Had the balance-valves only
been open it would probably not have happened at all ; nor,
perhaps, if one of the weighted-valves had been at liberty, as
probably the boat would not have remained so long at the
pier as to allow the pressure to reach the burst-
ing point. There was no necessity to lave • flat
front in this boiler. I should have preferred • convex
one. At the same time there is danger in a flat one
with stays ; but without stays, or with inefficient ones, they
are very i'angerou ones. To leave the valves in the power
of the engineer, is putting a temptation in his way which
few men are able to resist when they want to increase the
speed of their vessel.
By Mr. Lo Breton . I think • continuous pressure of 66
on this boiler would have been dangerous. Had it been the
common practice of the engineer to fasten down the valves
since April last the boiler must have been occasionally ex-
posed to • higher pressure; whether meth higher de-
pends on the power of the boiler to generate steam.
I do not think it possible that the boiler could have burst at
a much lower pr sauce than 136. The fact of the valves
having been tied down for some months, might not have
caused any appearance in the boiler which would attract the
notiee of Mr. Joyce, if he inspected it three weeks before
the accident.

By the Jury : A string to the end of the lever to shake It
is a matter of convenience, but there is no necestity for it.
If the front of the boiler had been made of Low Moor iron
is the parts principally exposed, the difference of cost
would have been quite inconsiderable ; perhaps 21. or 31.
I refer to the two plates in front. The balanco.valve, if
raised only a quarter of an Inch, would increase the resist-
ance from perhaps 20 lbs. to 24 lbs., and so on, fur every
further rise. The escape of steam front the engine-room
would not necessarily indicate that the valves were tied.
The iron in question is rolled iron, not east iron. I do not
think a greater number of tubes necessary • they are very
well proportioned to the rest of the boiler. la the navy it is
impossible to tie down the valves, because they have no
levers.—ELeft sittinfr.]
VIIITAGZ IN FRANCI.—A latter boa Moalwazdt
(COM d'Or), ear that the resent bad weather hes as debyed
dts dr4lasisof the grope, that no lisp is esawisewed of
ft Mats to brizpooi mid period Mgr
stem woks Ilion that of . NOM pato,. tits
soommoollosiog hovel, wldoit
hos a bed Gait Oa dot fruity of the wino.