and the Economy of Fuel. 165 



The double walls of the kiln, and the void space 

 between them, as also the horizontal layers of bricks 

 by which they are united, are clearly and distinctly 

 expressed in the figure. The kiln is represented as 

 being nearly filled with small round stones, such as are 

 used at Munich in burning lime. These stones are 

 brought down from the calcareous mountains on our 

 frontiers, by the river (the Isar), and are rounded by 

 rubbing against each other as they are rolled along 

 by the impetuosity of the torrent. 



[This paper is printed from the English edition of Rumford's Essays, 

 Vol. II., pp. 1-196.] 



