Steam Engine. S57 
Description oj Mr. Lloydh Patent Boiler for quick boih 
ing and saving fuel. 
The bottom of each of Mr. Lloyd’s boiler > is introvert- 
ed, so as to form a cavity which would nearly hold as 
much as the boiler itself, if it were reversed ; the sides of 
this cavity are somewhat conoidal, and from the top a pipe 
passes out at one side through the cavity of the boiler to 
the air ; the whole boiler or kettle, is surrounded by an 
external case, a little distant from it all rounds closed at 
top, and having a small opening at the side to give vent 
to the smoke. The small pipe adds somewhat to the ef- 
fect, but is not absolutely necessary. For large boilers 
the cavity at the bottom need not be so large in propor- 
tion as that described, if it rises into the boiler a third of 
its depth, it will probably be sufficient. The flame and 
radiant heat of the fuel is reverberated in all directions in 
the cavity of the hollow bottom^ and must have much 
more effect than what can be produced by its unconfined 
lateral action against the external sides of a number of up- 
right pipes however well arranged ; indeed Count Rum- 
ford has shewn in former papers, the value of the lateral 
action of fire against the sides to be so small, that we are 
surprized to see him recommend the apparatus above de- 
scribed, in which the chief effect produced must arise 
solely from a similar lateral action of the fire. 
• Account of a successful expriment in making soap by thd 
operation of steam^ instead of an open fire^ communica- 
ted by Count Rumford to the French National Insti- 
tute . Phil. Journ. No. 71. 
The steam was conveyed into the vessel, which con- 
tained the ley and other materials for the soap, by a pipe 
arising from a close boiler, and again descending into the 
I vessel ; the action of the steam in condensing in the cold 
I ley, occasioned a succession of smart shocks, similar to 
1 Vo!. II. Z z 
