20 



CIRCULAR NO. 130, BUREAU OF PLANT INDUSTRY. 



inches in diameter, were used for the outside rows in order to make 

 a more stable foundation. The smaller poles and slabs were placed 

 between the large outside jjoles; and these made u]3 the layer, except 

 for a stri]) 2 feet wide in the middle, where small wood and kindling 

 were placed the entire length of the kiln. Chinks between the poles 

 and slabs Avere filled with fine wood and cornstalks. 



Fine coal was then placed as a second layer to a depth of 2 inches. 

 On top of the coal was placed a 4 or 5 inch layer of limestone, 

 crushed to the size of a man's head or smaller. (Fig. 2.) Another 

 layer of coal was then added and this was followed by a layer of 

 limestone 12 to 11 inches thick. Alternate layers of coal and stone 

 were added to these until the pile was 7 or S feet high. The sides 



-S^ 



Fig. 2. — The kiln in tlie tliird step of building. A layer of coal is beins added to covei" 



the layer cf limestone. 



Avere gradually drawn in. making the pile somcAvhat pyramidal in 

 shape and draAA'ing it to a peak, and AAere then coaled up by shovel- 

 ing on as much as the crcA-ices AA-ould hold. The kiln Avas then ready 

 to be fired. 



METHOD OF BURNING. 



A fire Avas started on the AA^ndAA^ard end near the middle. Avhere 

 the strip of kindling had been placed. This gradually began to 

 burn. In a day or Iaa'o, as the fire began to burst out of the sides, 

 dirt AA'as shoAeled OA^er it to smother the fire and keep it from burn- 

 ing too rapidly. The burning of the kiln continued about two 

 AAeeks. After it liad cooled off. the dirt AA-as remoA'ed in order to 

 LCir. i;;o] 



