470 



CEMENTS, LIMES, AND PLASTERS. 



I. Dome or Ordinary Intermittent Kilns. 



All intermittent kilns will, for convenience, be here termed dome 

 kilns, though the term is properly restricted to intermittent kilns of 

 one particular shape. 



FIG. 107. Dome kiln 



The dome or bottle-shaped kiln is the original form on which most 

 fixed kilns are based. As shown in Fig. 107 it is practically the shape 

 of the older lime-kilns, differing usually in having a somewhat greater 

 height for a given diameter. The type shown in the figure, which is 

 the ordinary English form, is perhaps 9 to 12 feet in diameter at its 

 widest portion, 15 to 18 feet from its base to this widest zone, and 

 25 to 35 feet in total height. This kiln is usually charged at several 

 levels, one charging door being located a little below its widest point, 

 and others being opened in the truncated cone which serves as a chimney. 



In German practice these kilns assumed a form nearly like that 

 of the blast-furnace. The body of the German dome kiln is usually 



