252; 4 = Report of the Select Committee 
two-thirds of them have been locked up, but-I cannot exactly 
say; one is always exposed. 
Do you think any great security is produced by the operation 
of a mercurial gauge, as a safety-valve ?—Certainly so. . 
Are you of opinion, that by the adoption of those precautions, 
high pressure steam may be used with safety, either with wrought- 
iron or cast-iron boilers >—Perfectly so. 
_ In ease by accident of the explosion of a boiler—which would 
be attended with the greatest mischief, a cast- cr wrought-iron 
boiler ?—I should imagine the explosion would be one and the 
same. 
Would not the cast-iron boiler be more liable to burst in frag- 
ments, than the wrought iron ?—TI have never seen it; I have 
seen several cast-iron boilers rend, but never explode. 
Would not wrought-iron boilers rend?— Wrought-iron boilers 
rendalso. It appears to me it is not from the pressure, but from 
the heat where the water is kept from the place where the rend 
takes place ; I never saw a cast-iron boiler that had exploded. 
Supposing two vessels, one of cast iron and one of wrought 
iron, of equal dimensions, which have no escape-valves at all, to 
be burst by the expansive force of steam; from which of those 
two should you expect the greatest mischief to arise ?—From the 
cast iron. 
‘ Mr. Witutiam Bronton’s Evidence. 
What are you, and where do you reside?—I am a civil en- 
gineer, resident at Birmingham. 
You are a manufacturer of steam engines ?—Yes. 
Have you ever manufactured any steam engines for boats ?— 
Yes. 
Have you any thing to communicate to the Committee, for 
their information, respecting the best construction of the engine 
or boiler, to produce safety to passengers on board ?—Yes; I 
have, during the course of my experience, made several high 
pressure boilers, and in turning my attention to that, I was in- 
duced to examine what had been done before me; and I think 
we have accomplished the object, in making a boiler, which I 
apprehend will become useless before it becomes dangerous. 
Are you acquainted with any instances of the explosion of 
steam boilers ?—Yes, of both kinds ; I know of one which ex- 
ploded at Hunslet, near Leeds, whilst I was within half a mile 
of it ; it was a low pressure boiler; the cause was the weakness 
of the boiler, and the effect was, that all the windows of the 
neighbouring manufactory, which were of lead, were torn out, 
and there were a great number of the work-people scalded. 
Was 
