on Steam-Boats. 249 
Which would you, as an engineer, recommend to'be used on 
board steam-boats, wrought-iron or cast-iron boilers ?—I think 
both might be used with equal safety; but that in proving them, 
they ought to.be kept under the pressure a considerable time, 
Say a quarter of an hour or half an hour; sudden pressure may 
cause flaws in a boiler, which may give rise to accident after- 
wards; but if under pressure a considerable time, you might see 
the action of it. : 
Mr. Joun Ricnter’s Evidence. 
Where is your residence ?—In Cornwall Place. 
What are you >—A sugar refiner. 
Were you acquainted with the cirewmstances attending the — 
explosion of the engine at the sugar-house in Wellclose-square? 
—I was. 
Be so good as to state them ?—I had attended from time to 
time during the whole period of the construction of that boiler, 
for the purpose of boiling sugar by means of high pressure ; it 
was necessary we should have a pressure of from six-and-thirty 
to five-and-forty pounds to an inch. I saw the-boiler when the 
bottom only was put up, and I was at that time informed that 
they had cast the dome part of it, and that it was not sufficient, 
and that they were casting another. Some months afterwards 
I attended, and I found that other placed there. I saw them 
at work, and as I went in, Mr. Haigh, who was the engineer, 
told me they were boiling at eighteen pounds an inch ; to which 
I replied, that must be impossible; we have never been able to 
boil at. less than six-and-thirty. Upon which I went to the 
gauge, and [ found the index of the gauge standing at five- or 
six-and-thirty. 
What was the nature of that gauge ?—A mercurial gauge, in- 
tended as an index. I said, ‘ Surely you are mistaken, this is 
six-and-thirty.”” ‘Oh! no,”’ he said, ‘ that means eighteen.” 
In consequence of which, I took an opportunity of measuring the 
gauge, and found the gauge to represent inches, by which I 
knew they were in an error. [| measured to convince them of 
the error, but failed, and could not convince them of it till the 
day after the accident. In consequence of complaints from 
Constant, the Frenchman, in whose house it was, that it would 
not do its work, and his fears in pressing it on to do its work, 
the maker of it became anxious to show that it would, and a day 
was appointed for this to be done. Constant, at three o’clock 
in the morning, began his work, and continued boiling till about 
eight, but boiling with a great deal of difficulty, because he was 
afraid of putting the engine to the pressure he required. He 
gave 
