56 _ Report of the Select Committee 
malleable metals a simple rending generally takes place, it would 
seldom happen that the upper part of the boiler would be torn 
off; but iu 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 past ?—Yes. 
Did you ever hear of any other than the single instance that 
you have mentioned, in which a wrought-iron boiler burst in such 
a manner ?—No., 
Do you know what was the occasion of the top being blown 
off in the instance you mentioned ?—We cannot tell what was 
the immediate reason, but I suspected it to arise from the shape 
of the boiler. 
What was that shape ? —The bottom was of the usual waggon- 
shape boiler, convex inwards; the concave part of the boiler was 
over the fire, and those who examined it with myself imagined 
that the engine-keeper had suffered the water to he 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 a'l 
of them cast iron ?—TI believe they were; i never knew Le 
make any other. 
Mr. Woolf’s boiler has been in use nearly ten years >—T ihe 
lieve it has. 
Did you ever hear of anv 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, but 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 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 are safe from explosion 
in all instances ?-—Used with no further pressure than six pounds, 
What renders them safe?—Because they never employ steam 
of high expansive force in them. 
What are the means by which they are prevented from using 
steam of high expansive force in them ?—Because it would be 
against the interest of the persons using them 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 ?—Certainly 
none ; because I have known instances where they have used in 
the same engine both steam of a high expansive force, and con- 
densed it at the same time, 
/ 
You 
