ARTIFICIAL HEAT. 



Fiff. 22. 



317 



is given in Fig. 23. The fuel is supplied bj the door 

 at a, and is pressed down the inclined plane toward^ 

 the grate c, hj an apparatus placed at the head of 

 it; but this method, being complicated, has given way 



Fig. 23. 



wmrniuwrnjiin 



to several modifications, in which the door a has been 

 found the most useful, the fuel being pressed forward 

 by the common tools used for feeding furnaces : h is 

 the door for regulating the fuel on the grate c. In 

 its progress, the whole surface of the coal along the 

 inclined plane is constantly kept in a state of inflam- 

 mation, the flame having naturally a tendency to burn 

 upwards. In this way, the greater part of the fresh 



