244 Report of the Select Committee 
rivets in the larger ones; and I consider every rivet to be in @ 
degree a safety-valve, as in all instances of bursting or tearing of 
this description of boilers the rivets first give way, and always 
give sufficient warning. 
How many safety -valves have you to your boilers ?—One to each. 
Is that safety- valve accessible to the engineer directing the en- 
gine ?—It is inall of them excepting the Richmond, and there it 
is under lock and key; the safety-valve on board cf the Rich- 
mond is uot a lever safety-valve, but they are simple weights 
resting on the safety-valve, the whole of which is inclosed within 
a box and locked up, so that no discretionary power is left to 
the man who works the engine; , carry the key of it in general 
myself. 
‘Do not you think in future it aan be advisable, in order for 
the greater safety of passengers, that boilers should be provided 
with two safety- valves, one not accessible to the engineer direct- 
ing the engine, and another accessible to him ?—I think. that to all 
boilers there should be two safety valves; the one which would be 
accessible to the engine-worker, should, be loaded with the mini- 
mum of the pressure > that the chief engineer saw fit that the boiler 
should sustain ; and that the one which would be inaceessible and 
locked up, should be loaded equal to the ultimatum that he would, 
under any circumstances, permit the boiler to support. 
In a high pressure engine, what is your opinion of the weight 
that ought to be placed upon the safety-valve of its boiler ?— 
That in a great measure is conjectural ; but for my own practice, 
I certainly should not allow the safety-valves to be loaded with 
more than half the weight which I had previously tried and found 
the boiler was capable of supporting ; all my engines are low 
pressure engines, and the weight upon the safety-valves is re- 
gulated not to exceed six pounds upon the inch. 
What is the reason that you have adopted, in your steam- 
boats, the construction of boilers with flat sides and ends ?— 
Because that figure gives the greatest cubical content in the 
smallest space, and compactness of the machinery and the boiler 
is a desirable object in a steam-boat. 
Is it your opinion, that such boilers properly constructed, and 
of sufficient thickness in the plates of wrought iron, may be safely 
used on board steam-boats having the low pressure engines ?— 
Most decidedly so; I consider each of my boilers capable of 
sustaining a pressure of fifteen pounds upon the inch, but I never 
work them to more than six.pounds upon the inch. 
Are those boilers so constructed, that the water entirely covers 
the tube in which the fire is made In the Richmond, the fire 
is entirely surrounded by the water; it is the case lee in the 
Majestic; but in the Thames and in the new boat to Richmond, 
‘and 
