176 Report of the Select Committee 
without reference to the character of the engine at all, whether 
it was a condensing or high pressure engine. All boilers on 
, board; steam-boats should have the fire in the interior of the 
boiler, because it is of very little importance, when you are upon 
ethe subjec: of safety, whether the passengers are to be endangered 
by an explosion, or whether the vessel is to he weakened in its 
-timbers or essential securities by the improper application of the 
fire to the boiler: therefore, I invariably recommend, that the 
fire should be ‘contained in the interior of the boiler, and that 
‘there should be an additional safety-valve, which should be solely 
‘subject to the superintendence of the proprietor, and that the 
‘manager of the machine should have no possible access to it. 
That you mean to apply, whether high pressure or low pres- 
‘sure boilers are used ?—Both; because I am quite aware, that 
-if a boiler in a steam-boat is to have the fire to operate upon it 
vexternally, although you may not explode the engine, you may 
so far destroy the vessel that carries the engine by burning its 
timbers, without the knowledge of the individuals to whose care 
the boat is intrusted, as to be highly injurious and misehievous 
to the safety of the passengers. I should certainly recommend 
‘a wrought-metal boiler in preference to a cast-iron boiler ; and 
the reason is clear, that the operation of casting, however skil- 
fully managed, is always an uncertain process. An oecurrence 
took place a few days ago, which very much staggered me; I 
had a large press of cast iron, which it was necessary to break 
up, and in the interior of a bar which was probably eight inches 
‘by twelve, there was a cavity in the centre of four inches dia- 
meter, with no external communication. 
-« Do you think that a safety-valve may not be so constructed, 
_ a8 that its operation shall not be impeded in any degree by the 
ase engineer to whose care the vessel is committed, and yet with a 
tolerable certainty of its operating to all its proper intents and 
purposes ?—If an additional safety-valve was applied to a boiler, 
and that safety-valve placed beyond the power of being inter- 
fered with by any person but the proprietor, then the boiler 
would be secure from explosion, if the safety-valve should be 
judiciously loaded ; but if, that safety-valve was even placed be- 
yond the reach of the operator, and at the same time injudiciously 
loaded, a calamity might take place the same as if no such se- 
curity existed. 
_. Allowing thet under all possible circumstances a condensing 
engine should be the most safe, what is your opinion as to the 
sufficient safety of a high pressureengine, of which the boiler and 
safety-valves should be constructed in. the manner which you _ 
have just nowdescribed ?—I should consider a highypressure en- 
2 ey ate Ren ed aera >, gine, 
mS ; 
