248 



HOPS. 



The air is drawn lout from the kiln chamber by exhaust 

 fans, and discharged into a cooling chamber, on the walls of 

 which the moisture is deposited ; whence, after being warmed 

 again to the requisite degree in an adjoining chamber, it is 



Fig. 74. — The Andrlik and Hueber kiln. 



returned to the kiln to resume its circulation. The drymg 

 of the air can also be effected by means of suitable hygro- 

 scopic substances. 



Another new system is that of K. Zorner, of Libotschan, 

 who uses revolving frame boxes, and claims to effect very 



