MUSHROOM. 195 



the north part, if convenient and not too much ex- 

 posed, may be built against any spare place to that 

 aspect, which will save some expense. The wall 

 should be nine feet high, from the surface of nine 

 inch work. It should have a double roof; for the 

 inside one, an arch made of thin boards, the ends 

 to rest next the wall on the upper shelf, and the 

 outer one a span, covered with slates or tiles. At 

 eighteen inches' distance from the wall inside the 

 house, should be fixed five or six upright posts 

 on each side, to which cross wooden bars may be 

 fastened, whose ends next the wall may be mortised 

 in it. Three tiers of shelves or boxes of the above 

 breadth must be obtained and placed thus : the 

 first or lower tier, two feet from the ground, the 

 second four feet, and the third six feet. A small 

 flue of seven or eight inches should be set on flat 

 bricks, every other one open, commencing at the 

 east, and going round next the path of fourteen 

 inches ; which is better than to place the flue im- 

 mediately under the lower tier of shelves, as this 

 would be prejudicial from its heat, though little 

 danger need be apprehended on this ground, as the 

 maximum heat of the house in the severest season 

 should not exceed 60 ; the average about 55. How- 

 ever, for fear of accidents a tile should be placed at 

 the lower end of the uprights, between them and the 

 flue, by which any apprehension of danger may be 

 removed. The door of the house should have a 

 small slide made at the bottom, which may be used 

 occasionally as a ventilator. 



In the above sketch it will be observed that 

 bearers are fixed to support shelves or boxes, 

 o 2 



