50 ON THE GROWTH OF THE CUCUMBER 



up even with the top of the twelve courses 

 before adverted to. The whole must then be 

 covered over by a course of headers ; that is, a 

 course laid cross-ways, which will cover the four- 

 inch wall, the cavity, and the brick-on-edge, 

 thereby forming a chamber between them, from 

 thence to the ground, for the reception of the 

 heated air, as well as for giving stability to the 

 work. Then continue three additional courses 

 of four-inch solid, which will leave a projection 

 of five inches on the inside of the pit for the 

 trellis to rest on. The front or outside will then 

 be* sixteen courses high, or four feet. Having 

 finished the front, let the back have five courses 

 of pigeon-holes, and ten of four inches solid ; 

 then of the brick-on-edge inside, to form the 

 chamber as before eleven courses, which will be 

 one foot higher than the other side ; the whole 

 must then be covered as before with headers, or 

 cross-ways ; then four courses of single brick to 

 finish, making in all twenty-one courses, or five 

 feet three inches high. If the four-inch work 



