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THE POPULAR SCIENCE MONTHLY. 



the sublimed sulphur collects. At one end of the chamber is a vertical 

 chimney, I, provided with a damper, K. 



The kiln is charged in the usual way by placing the large pieces 

 of ore on the floor in such a manner as to leave passages for the flow 

 of the liquid sulphur ; the small pieces are next filled in, and the finer 

 ore at the top. A few blocks of rough stone, or burned ore, are placed 

 at the opening in front in such a way as to leave a vacant place for 

 the melted sulphur to collect before being run off. When charged, 

 the ore is covered with bricks laid flat, and on these is put a layer of 

 genese, well rammed and wetted, so as to form a nearly impermeable 



Fia. 3. 



coating, with a slight slope toward the walls, in order that the rain- 

 water may run off. The opening, F, in the front wall should be closed 

 with a thin wall of plaster of Paris. The ore in the kiln, which is now 

 ready for fusion, is put in communication with the spent calcarone, B, 

 by opening the damper, D, and at the same time a small hole, N, is 

 made in the wall that closes the opening in front, from which the melted 

 sulphur has been run off from the calcarone, B. The current of air 

 entering by the hole, N, and passing through the incandescent mass 

 of ore, is thus heated, and enters the kiln by the flue, N, at a sufficient 

 temperature. In this manner the heated mass of spent ore in the cal- 

 carone becomes a regenerator of heat, to be utilized in the kiln for the 

 fusion of the sulphur that it contains. In the upper covering, two or 

 more tubes, O P, are placed, and serve not only for observing the in- 

 ternal temperature by a thermometer, but also for firing the mass. 



The combustion of the sulphur supplied with hot air, mixed with 

 a considerable proportion of sulphurous-acid gas, proceeds slowly in 

 the upper part of the kiln, and the liquid sulphur dropping to the floor, 

 over the already heated ore, can not solidify and choke the passages, and 

 so prevent the circulation of the heated air and products of combustion 

 of the sulphur to the chimney ; in this manner the operation proceeds 

 with regularity. The success of the kiln is principally due to the 



