and the Economy of Fuel. 163 



method of fitting the door to its frame have already 

 been explained. (See descriptions of the Plate II.) 



PLATE VI. 



Fig. 25 is a section of a small lime-kiln, built, or rather 

 now building, at Munich, for the purpose of making 

 experiments. The height of the kiln is 15 feet; its 

 internal diameter below, 2 feet; and above, 9 inches. 

 In order more effectually to confine the heat, its walls, 

 which are of bricks and very thin, are double, and the 

 cavity between them is filled with dry wood ashes. To 

 give greater strength to the fabric, these two walls are 

 connected in different places by horizontal layers of 

 bricks which unite them firmly. 



a is the opening by which the fuel is put into the 

 fire-place. Through this opening the air descends which 

 feeds the fire. The fire-place is represented nearly full 

 of coals, and the flame passing off laterally into the 

 cavity of the kiln, by an opening made for that purpose 

 at the bottom of the fire-place. 



The opening above, by which the fuel is introduced 

 into the fire-place, is covered by a plate of iron, movable 

 on hinges ; which plate, by being lifted up more or less 

 by means of a chain, serves as a register for regulating 

 the fire. 



A section of this plate, and of the chain by which it 

 is supported, are shown in the figure. 



b is an opening in the front wall of the fire-place, which 

 serves occasionally for cleaning out the fire-place and 

 the opening by which the flame passes from the fire-place 

 into the kiln. This opening, which must never be quite 

 closed, serves likewise for admitting a small quantity 



