on Steam-Boats. 87 
terests and different companies. Mr. Evans being a patentee, 
they have to give something for the use of his patent ;—if they 
cannot make their bargain with him they use the low pressure 
engine; but there is a new engine invented in America, a per- 
fectly rotatory engine, built for one-third of the money, which is 
now coming into use in several of the steam-boats; and it was 
supposed when I came away it would supersede all other en- 
gines. 
Do you know of any particular guard in the construction of 
steam-engines used in America to prevent accidents ?—I know of 
no other than that of properly constructing the safety-valve, and 
the manner of loading it, so that they cannot get on more than 
a certain weight ; they must of course construct them strong 
enough and prove them. 
They are under no Government regulation >—They are not. 
Does that with a rotatory motion consume more coals ?—It 
is supposed to consume less; twelve bushels of coals with the 
rotatory motion will perform the same work as the other engine 
with twenty. 
Mr. Timotuy Braman’s Evidence. 
You are an engineer, at Pimlico ?>—I am. 
You were one of the gentlemen that went to Norwich to in- 
quire into the explosion of the steam-boat ?—I was. 
Did you go at the request of any party, or of your own volun- 
tary suggestion ?—I went in consequence of my friends, Mr. Col- 
linge and Mr. Donkin, calling upon me to ask my opinion, 
whether it would be right for us to interfere upon such an oc- 
casion; I concurred with them that it would, and volunteered 
tO go. 
Your design was to inquire into the causes of the explosion? 
—Yes, and to examine as much of the wreck as we could find. 
State to the Committee to what you attribute the accident? 
—The observations I made led me to determine it was owing to 
the expansive force of the steam, and the inadequacy of the boiler 
to sustain that force. 
Was it a high pressure or a low pressure engine?—A high 
pressure engine; the boiler was badly constructed and shaped. 
Of what materials was the boiler composed ?-——Of wrought 
and cast iron, and it was the cast-iron part that gave way. 
Those two materials expand in a different proportion with the 
same degree of heat ?—Yes, they do. 
Is it usual to have the boiler of wrought and cast iron?—I 
should think it would be avoided on all occasions by experienced 
engineers ; but I have often seen it, 
This 
