50 



Professor W. A. Bone 



[Feb. 27, 



It is obvious that this process is capable of adaptation to all kinds 

 of furnace operations, as, for example, to the heating of crucibles, 

 muffles, retorts, and to annealing and forging furnaces generally. 

 Moreover, it is not essential that the 'bed of refractory material 

 should be very deep ; indeed a quite shallow bed suffices to complete 

 the combustion. Neither is it necessary that the bed shall be disposed 

 around the vessel or chamber to be heated ; for if contact with the 

 burnt products is not objectionable, a shallow bed may be arranged 



Fig. 5. 



within the heating chamber itself (Fig. 7) ; or the refractory material 

 may be equally well packed into tubes, or the like, traversing the 

 substance or medium to be heated. The last-named ^modification is, 

 as we shall see later, specially important in relation; to steam-raising 

 in multitubular boilers. 



By means of this process much higher temperatures are attainable 

 with a given gas than by the ordinary methods of flame 'combustion 

 without a regenerative system, and, as a matter of fact, we have found 



