in closed Fire-places. 493 



place to give admittance to a little fresh air to facilitate 

 and excite the combustion, the flame became so exceed- 

 ingly vivid and clear that I promised myself great 

 advantages from this new arrangement. 



Being soon after engaged in putting up a large 

 square boiler in the kitchen of the Foundling Hospital, 

 I there introduced the same contrivance ; but how 

 great was my surprise on finding that, notwithstanding 

 the extreme vivacity of the fire, the contents of the 

 boiler could not be brought to boil in less time than 

 five hours! The fire-place, it is true, was small, and 

 the brick-work was new and wet ; but I found that the 

 quantity of coals consumed was such that, had there 

 been no essential fault in the construction of the fire- 

 place, nor in the management of the fire, the contents 

 of the boiler ought, notwithstanding these unfavourable 

 circumstances, to have boiled in less than one third 

 part of the time that had been found necessary to bring 

 it into a state of ebullition. 



Having wasted two or three days in attempting to 

 remedy the defects of this fire-place, without changing 

 entirely the principles of its construction; concealing 

 my disappointment from those who it was necessary 

 should have confidence in my skill, by representing to 

 them all that had been done as being a mere exper- 

 iment, I pulled down the work to the foundation, and 

 caused it to be rebuilt on principles which I knew 

 could not fail to succeed, and which did succeed to 

 the utmost of my expectations. 



Though I ruminated often on this disappointment, I 

 did not find out the real cause of my ill success for some 

 months. This discovery was, however, at length made, 

 and in such a manner as to leave no room for doubt. 



