on Steam-Boats, §1 
if the low pressure boiler by any accident should be exploded, 
generally speaking, boilers made of the malleable metals must be 
much safer on an explosion taking place, at. least they are not 
calculated -to do so much mischief as the cast-iron boilers. 
Have you made any experiments, or are you acquainted ac- 
curately with the effect of such as have been made upon the dif- 
ferent quantities of fuel consumed in the high and the low pressure 
engines, in proportion to the quantity of power produced ?—I 
have witnessed several experiments on Woolf’s engines, where 
the object was to ascertain the comparative expenditure of coals 
or fuel in grinding corn between his engines and the low pressure 
or condensing engines, and. the results were decidedly in favour 
of Mr. Woolf’s engines. 
You cannot speak as to the high pressure engines commonly 
in use ?—I apprehend there is no saving of fuel, or very little ; 
there may be a little. 
What was the saving of fuel by Woolf’s engine, as compared 
with the other?— The average effect in one case was the grinding 
eighteen bushels of wheat with one bushel of coals; the other 
average effect of Bolton and Watt’s engine, or the low pressure 
engines, is the grinding of from ten to twelve bushels of wheat 
with a bushel of coals, 
Do you know whether the power of the engines in lifting water, 
may fairly be reckoned at the same proportionable difference ?— 
Yes; I believe they may. [do not speak from experiments; 
but [ have no doubt as to the effect ; by the reports from Corn- 
wall, I am led to suppose it may be much greater. 
Have you seen any account of the-explosion of the steam- 
engine on board a boat in America, within a few weeks past ?>— 
No; {have not. I understand there has been one. 
From any information you received at Norwich, did you hear 
of any conduct of the manager of that boat, which occasioned 
the explosion of the boiler?—-No; the information I did re- 
ceive upon that subject, was since we returned to London. 
Mr. Tuomas Lean’s Svidence. 
Will you state your profession, and place of abode ?—I reside 
at Crowan in Cornwall, and I am employed by nearly the whale 
of the miners in Cornwall to inspect their engines, and make 
anouthly reports of the work they perform. 
You are then well acquainted with steam-engines of every va- 
rions construction ?—Certainly I am; I see fifty-seven every 
month. 
Do you conceive that there is any material difference in the 
respective safety of those engines?—Some of the engines are 
«certainly safer than others, B 
e 
