CONSTRUCTION OF THE OVEN. 



In the middle of the house, a hole must be dug, of 

 which the size and depth must be proportioned to the di- 

 mensions of the nurserj. The ordinary size of this hole 

 ought to be four feet square. On the four sides, a square 

 brick wall, cemented with mortar, must be raised two feet in 

 height. COW T dung must be taken well dried, and reduced 

 to powder, and the bottom of the hole must be covered 

 with a bed of this powder, three or four inches thick. 

 Above, a layer of small pieces of dry wood must be spread, 

 at least five inches in diameter, which has been cut in the 

 last month of the year. Mulberry, acacia, elm, or any 

 kind of hard and solid wood may be used. Upon these 

 pieces of wood spread a second bed of dry and pulverized 

 cow dung. In the empty places, between each piece of 

 wood, the pulverized cow dung must be well beaten down 

 so as not to leave the smallest space ; for if an empty space 

 be left, the fire will produce flame, which may injure the 

 house, and besides, this fire would not last for any length of 

 time. When the hole is completely filled, and the pulver- 

 ized cow dung, that covers the pieces of wood and fills the 

 spaces between, is well pressed down, a bed of the same 

 matter must be spread on. Seven or eight days before the 

 hatching of the silk worms, live coals must be put on the 

 dry cow dung and covered over with hot ashes. 



The dry cow dung takes fire, and emits for six or seven 

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