on Steam-Boats. 245 
and the new boat to Gravesend, they are what we call open fur- 
Mace mouths: under the furnace mouth I place an ash-hole of | 
east iron, bedded iu clay and upon fire-bricks. 
Does the water in the boilers of this latter construction come 
to the upper surface of every portion of that iron, the under sur- 
face of which is exposed to the fire ?—It does. 
If you are acquainted with any accidents which have happened 
to steam-engines, not under your own direction, be pleased to 
mention what they were and how they happened ?—I recollect 
the boiler of the Caledonia London and Margate steam-packet 
bursting at sea, by the forcing out of three of the rivets over the 
furnace mouth, which extinguished the fire, but it was not pro- 
ductive of any injurious consequences to any of the persons on 
board ; and the Cork and Cove packet- -boat in Ireland, with 
250 officers and soldiers on board, burst her boiler when lying 
alongside of the transport that was receiving the troops; the 
bursting made a fissure or opening of nine inches by eighteen 
inches; but the steam which escaped did no injury either to the 
persons on board or to the vessel, nor do I think under any cir- 
cumstances of the bursting, if a wrought-iron boiler at the low 
pressure, that is, the steam not being more than ten or fifteen 
pounds to the inch, that the steam which might be suddenly let 
loose or disengaged, would have power sufficient to raise the deck 
of the vessel, or, to injure the parties on board. 
Supposing an engine upon the high pressure principle to have 
its boiler made of wrought iron, with the furnace passing through 
water throughout its whole length, and the boiler to be provided 
with safety-valves properly adjusted, so as to prevent the steam 
being raised to more than half of that pressure which the boiler 
is calculated to sustain, should you then have any apprehension 
of ill effects arising from the use of such an engine ?—Certainly, 
I should still consider them hazardous and liable to very fatal 
consequences ; for all boilers deteriorate by work, by time, and 
by oxidation, and what might be proof at this period, at a future 
period the boiler might be incapable of sustaining. Besides, all 
boilers are liable to casialties; and in ease of any accident which 
might. suddenly let loose or disengage the steam of a high pres- 
sure boiler, the steam itself would have sufficient expansive force 
and impetus to destroy any vessel. I have known instances, as 
I have stated before, ‘of low pressure engines bursting, where 
they have done no injury; but [ cannot conceive it possible that 
steam of ten or twenty times greater force could be let loose into 
the engine-room without creating mischief. 
What is the average price of steam-boats calculated to convey 
passengers ?—The Richmond steam-yacht cost, in the first in- 
stance, including the engine, 18004, the engine itself cost about 
