and the Economy of fuel. 9 



and was continued boiling two hours. The time em- 

 ployed and wood consumed in this experiment were as 

 follows : 



Time employed. Wood consumed. 



h. in. Ibs. 



To make the water boil . . I I 1 1 



To keep the water boiling ..20 2<| 



Total 



Experiment No. 2. The same boiler, containing 

 the same quantity of water at the same temperature, 

 being now removed to the kitchen of a private gentle- 

 man in the neighbourhood (Baron de Schwachheim, 

 a brother of the Commandant of the Academy), and 

 placed upon a tripod, a quantity of the same kind of 

 wood used in the former experiment being provided, 

 a fire was lighted under it by the gentleman's cook 

 (directions having been given to be as sparing as pos- 

 sible of fuel), and it was made to boil and continued 

 boiling two hours. 



The result of the experiment was as follows : 



Time employed. Wood consumed. 

 h. in. Ibs. 



To make the water boil . . I 31 45 



To keep it boiling ....20 17^ 



Total ....... 3 31 624 



As in these two experiments the same boiler was 

 employed ; as the quantity of water was the same, as 

 also its temperature at the beginning of the experi- 

 ments ; and as it was made to continue boiling during 

 the same length of time, it is evident that the quantities 

 of wood consumed show the relative advantages of the 

 different methods employed in the management of the 

 fire. The difference of these quantities of fuel is very 

 great (the one being only 13^ Ibs. and the other 



