and the Economy of Fuel. 69 



tion I supposed that, when the water began to boil, 

 there was wood enough in the fire-place unconsumed 

 to keep the water boiling 43 minutes, and that the 

 wood added afterwards (100 Ibs.) kept the water boil- 

 ing the remainder of the time it boiled, or just 2 

 hours. 



In most cases, however, to save trouble in making 

 these computations, I have supposed that all the wood 

 employed in making the water boil is entirely consumed 

 in that process, and that all the heat expended in keep- 

 ing the ivater boiling is furnished by the fuel which is 

 added after the water had begun to boiL This suppo- 

 sition is evidently erroneous ; but, as the computation 

 in question can at best give but an inaccurate and 

 doubtful result, labour bestowed on it would be thrown 

 away. But, imperfect as these rough estimates are, 

 they will however in many cases be found useful. 



In giving an account of the following experiments, 

 I shall not place them exactly in the order in which 

 they were made, but shall arrange them in such a man- 

 ner as I shall think best, in order that the information 

 derived from their results may appear in a clear point 

 of view. 



For greater convenience in referring to them, I shall 

 number them all ; and as I have already given num- 

 bers to the four I mentioned in the first chapter of this 

 Essay, I shall proceed in regular order with the rest. 



Experiment No. 5. The first kitchen of the House 

 of Industry at Munich has already been described in 

 the first chapter of this Essay ; and it was there men- 

 tioned that the daily expense of fuel in that kitchen, 

 when food (peas-soup) was prepared for 1000 persons, 

 amounted to 300 Ibs. in weight of dry beech-wood. 



