CLAY WORKING INDUSTRIES. 179 



through the bag which acts as a combustion chamber up into the kiln. 

 The incline grate allows the air to play freely beneath the fire, but 

 also allows the burner to see that no air holes are allowed to form through 

 the coals to the interior. The bars being loose are easily moved about in 

 cleaning the fires. The loss of heat by radiation is large ; the fuel is piled 

 up level with top of the fireplace when freshly replenished, but as soon 

 as it burns a few moments, it settles down allowing a constant stream of 

 outside air to flow into the fireplace over the surface of the fire. This air 

 is often needed to promote good combustion but in this type of fireplace 

 it is not under control and frequently much more than needed is allowed 

 to enter. 



4th. " The closed front, inclined grate bar fireplace" in use on the 

 Akron stoneware and sewer-pipe kilns, is one of the best fire places in use. 

 It is fired from the end as in the preceding, but the front is arranged to 

 be closed tight by a door or tile and the only influx of air into the kiln 

 except that which works through the mass of hot coals on the incline 

 grate, is admitted from small holes in rear of the firedoor and which are 

 under control of the burner. 



The character of the work of this fireplace is of the highest type; 

 it is practically a gas producer, applied to the needs of the brick kiln; no 

 better control of the work of the fire can be had by any means, but in 

 cleaning the clinkers out from the grates some inconvenience is felt, 

 especially when burning the fireplace for six or eight day campaigns ; in 

 its original work it was never necessary to clean the fire thoroughly dur- 

 ing the progress of the short burn. 



5th. The last important type of fireplace is hard to describe by a 

 name. It is fired from above, not from the end as before and no grate 

 bars are used. The fireplace consists of a space eighteen inches wide by 

 th ee feet deep and extending from the bag wall inside to about eighteen 

 inches beyond the kiln in the outside. 



The front is closed by a permanent or movable brick wall, leaving an 

 aperture about 18x18 below it to serve for an ashdoor; on top, the 

 aperture is 18x18 and is provided with a tile or metal cover. Across the 

 fireplace close to the circumference of the kiln, a 12x24 tile is placed ver- 

 tically on its edge, its top flush with the top of the fireplace. This serves 

 to make a false front for the fire and to hold it back from dropping down 

 into the foot of the bag too far. Between the tile and the kiln wall a 

 small space is left which on being opened or closed acts as a damper in 

 controlling the fireplace and perfecting the combustion. 



It is impossible for any air supply to get into the kiln except what 

 passes up through the fire from the ash door and down through the fire 

 from above. Hence all the air is converted into combustible gases which 

 continue in combustion through the bags and into the kiln. 



The advantages of this fire are : 1st. There are no grate bars to burn 

 out. 2d. It can be cleaned from clinkers with the greastest possible 

 facility and the least loss of heat. 3rd. The character and amount of the 



