CARBONIZATION OF TURI". }35 



By the chimney it may be observed, that the superior 

 aperture is less than the inferior, which is indispensable in 

 this construction ; aud this leads me to say, that there al- 

 ways exists a direct ratio between the apertures of the fire- 

 place, the ash-hole, the place where the smoke enters into 

 the chimney, and that at which it finds its exit, which 

 should always be proportional to the height. Thus ash- 

 holcs of a moderate depth and aperture, fire-places narrow 

 and well closed, turns (chicanes) artfully managed, and a 

 convenient issue for the smoke, all united constitute a 

 furnace, the good qualities of which are demonstrated by 

 experience. See Fig. 1. 



The second part of my apparatus, which I call thermo- Thermolamp. 

 lampic, is so arranged, that its lower part is horizontal, 

 and forms a long square. The upper part of its whole 

 length is an elliptical arch, terminated at each extremity by 

 a vertical plane, in the middle of which is a funnel or tube 

 bent at a right angle, serving to convey the products that 

 arise by distillation into the middle of a condenser, con- Condenser, 

 sisting either of a stone hollowed out, and covered by a 

 plank well luted to it, of a small wooden cask standing up- 

 right, or of a cast iron tube surrounded by a stream of 

 water. From these issue tubes to convey the inflammable Gas pipes, 

 gasses into the fire-place, that they may serve, as I men- 

 tioned above, instead of part of the fuel employed. The 

 funnels above described are furnished each with a key, to 

 intercept the communication between the outer air and the 

 charcoal, Avhile still hot : for experience has proved, that 

 charcoal thus prepared is capable of spontaneous aceension. 

 This phenomenon, it is said, may take place in large heaps Charcoal 



of charcoal Ions prepared : and, though I confess I never kindled s P on ~ 



nrr .. . . , taneously. 



Saw such an accident, it is certainly priulent to guard 



against it by currents of cold air traversing the heap in 

 various directions. See Fig. 3. 



The material of which the thermolampic apparatus is Materia!. 

 composed should be sheet iron, or thin cast iron ; though 

 one or more common cylinders may be substituted instead, 

 placed in a suitable manner, and furnished at their extre- 

 mities with tubes for conveying off the gaseous products, 

 &c. ; taking care that one end may be opened by means of 

 3 a hook. 



