THE HILL-KlLN. 



21? 



On the other hand, the packing in horizontal laying is extremely- 

 irregular and requires infinite pains to do well, and also consumes 

 much time. It is for this reason that the overground form, the 

 hurning in which is so much easier to conduct, is so often given up 

 for the rather primitive pit-form here described, in which loose 

 and careless packing has not the same serious consequences. Al- 

 though no exact figures are available, there are suflSicient data to 

 prove that the yield in pit-kiln burning is very much less than in 

 overground burning, the outturn of charcoal seldom exceeding 15 

 per cent, of the wood used. It is, however, well adapted for char- 

 coal manufacture on a small scale when skilful burners are not 

 obtainable. The local name in the Dehra Diin for the pit^kiln is 

 hliadi ha bhatta, literally, the carpenter's kiln. 



Aeticle 3. — The Hill-Kiln. 



On hillsides the construction of any of the kilns hitherto des- 

 cribed is out of the question ; a level site of even quality could be 

 obtained there only at prohibitive expense, and the draught from 

 the four sides can never be made equal, being always greatest from 

 the side of the valley and almost totally wanting on the side of the 

 hill. Hence the necessity of constructing a special kind of kiln. 



The terrace on which the kiln is to be built should be made to 

 slope slightly outwards. The outer portion of the terrace, beino- 

 necessarily made-ground and open towards the valley, is pretty 

 freely penetrable to air. To neutralise this inequality, which is 

 still further exaggerated by the absence of any draught from the 

 side of the hill, the largest and hardest and greenest pieces should 

 be packed at the valley end of the kiln, which should also be built 

 up highest. Moreover, the kiln should, for obvious reasons, be 

 made to lean up against the hill, and to this end the side of the 

 hill should not be cut vertical but sloping at an angle of about 30° 

 (.w Fiff. 69). 



Fig. 69. 



mil-Kiln. 

 1 1 Twmel for firing kiln. 



V Vent-hole. 



2 p 



