and the Economy of Fuel. 75 



is not so great as the difference in the weights of the 

 quantities of wood used in the two experiments. To 

 estimate that saving with precision, the wood should be 

 weighed before it is dried, or in the same state in which 

 the other parcel of wood, which is used without being 

 dried, is weighed. 



But to proceed to the principal object I had in view 

 in these experiments, the determination of the effects 

 of the difference in the construction of the two fire- 

 places, the difference in the quantity of fuel expended 

 in the two fire-places, in performing the same process, 

 shows, in a manner which does not stand in need of any 

 illustration, how much had been gained by the improve- 

 ments which had been introduced. 



Conceiving it to be an object of great importance to 

 ascertain by actual experiment, and with as much pre- 

 cision as possible, the real amount of the advantages, 

 in regard to the economy of fuel, that may be derived 

 from improvements in the forms of fire-places, I did not 

 content myself with improving from time to time the 

 kitchens I had constructed, but I took pains to deter- 

 mine how much I had gained by each alteration that 

 was made. This was necessary, not only to furnish 

 myself with more forcible arguments to induce others 

 to adopt my improvements, but also to satisfy myself 

 with regard to the progress I made in my investiga- 

 tions. 



In the first arrangement of the kitchen of the Mili- 

 tary Academy, the boilers were suspended by their rims 

 in the brick-work in such a manner that the flame could 

 pass freely all round them, and the smoke went off in 

 horizontal canals which led to the chimney, but which 

 were not furnished with dampers. 



