with a Ground Plan and Elevation of the Pits. 387 



WmSm 





Ft. 



three, six, or more lights, as re- 

 quired, may be worked in succes- 

 sion. The dung in these openings, 

 when once put in, is not to be turned 

 like the linings ; since, as the pits 

 are pigeon-holed, and without flues 

 at the ends, the roots will work 

 through, and receive a deal of 

 nourishment from the dung in the 

 openings when it is decayed. These 

 openings are likewise exceedingly 

 serviceable in cold or damp weather, 

 as they afford the opportunity of 

 topping up all round with fresh 

 dung. The plan (Jig. 74.) shows 

 the beginning of my cucumber and 

 early melon range, which has nine- 

 teen lights. It begins with two 

 lights, and ends with the same, but 

 the intervening length is divided into 

 pits of three lights each, with open- 

 ings between, as before stated, a is 

 10 Ft the outside wall of the pit, which is 

 of 4-inch brickwork, pigeon-holed 

 all round, as shown in the elevation ; b is a brick-on-edge wall, 

 worked up solid, except one row of pigeon-holes at the bottom, 

 left for drainage. This inner wall must be brought up one course 

 higher than the pigeon-holes in the 4-inch work, or outer wall ; 

 and, by covering the cavity between this and the outer wall 

 with a double layer of plain thin 6-inch tiles, it forms a flue 

 back and front. The plain tiles require to be double, be- 

 cause the centre of each tile which finishes the flue must be 

 firmly bedded over the joints of those first laid. This must 

 be particularly attended to, as the flue must be made steam- 

 tight. The advantage of this flue must be obvious to the most 

 superficial observer, as, by it, the violent bottom heat from the 

 linings, which is the bane of all forcing, is moderated ; and, as 

 much of the heat is transmitted through the tiles, it diffuses a mild 

 and genial warmth, which is circulated among the plants, with- 

 out there being any danger of too much heat among the roots. 

 It will here be necessary for me to observe that the centre of 

 my pits is filled up entirely with mould as high as the flues, 

 except about six inches of fresh turf chopped to pieces with the 

 spade, to be put into the bottom for drainage. This I con- 

 sider by far the best material that can be used for this pur- 

 pose, and the plants will show the benefit they derive from it as 

 soon as their roots begin to touch it. c is the cavity for the 



