616 



Queries and Answers. 



118 



i 1 P 



1 if 

 i 





n. °o | 



L Jl 



W TI 



tried. In pits recently constructed in Sir Giffin Wilson's gardens, Woburn 

 House, near Beaconsfield, Bucks (which were left to my direction), I have 

 grown cucumbers, French beans, potatoes, strawberries, and melons to per- 

 fection; and, as they are, I believe, the first pits which have been heated at 

 bottom on the following plan, I subjoin a sketch. (Jig. 118.) The wall is 

 built of 4-in. brick-work, the back 4 ft. high, the front 2 ft. 9 in., 55 ft. long, 

 and 6 ft. wide ; it is divided into four divisions, but the two next the boiler 

 are heated at bottom. The boiler (a) is a plain dome : b is the fireplace. 

 The heated water passes out of the neck of the boiler into a 3-in. pipe (c), 

 going all round the pits, and entering the bottom of the boiler, dis a branch 

 cross pipe, flanged to back and front main pipe in the middle of the pit ; e e, 

 stop-cocks, to turn the water off if not wanted in the third and fourth 

 divisions, /is a 2-in. lead pipe flanged to pipes (d and c) at the bottom of 

 the boiler, passing through two long wooden boxes or troughs (gg) lined 

 with lead (the first box 7 ft. long, 1 ft. wide, 9 in. deep, the second 9 ft. long), 

 and filled with water from a small cistern (h) in the end of the wall, close 

 to the fireplace, i, a |-in. pipe, going from the cistern, and soldered to box 

 g. The one box fills the other through the J-in. pipe ( /), which serves to 

 fill and empty, k is a small pipe, soldered to bottom of box g, with a cock 

 (/) to empty both at pleasure. The water circulates freely, and very soon 

 warms that in the boxes, causing a fine moist bottom or under ground heat. 

 m,& bottom made of wooden rails, 2 in. apart, laid over the pipes and boxes ; 

 n, a thin board laid over this bottom, exactly above the boxes, to prevent 

 the mould from dropping through, on which and all over the wood-work is 

 a layer of turf. This bottom stands clear of the pipes and boxes, forming a 

 chamber under the mould. Two holes (o o) are cut in the board, and two 

 tubes of 2-in. pipe, 2 ft. 9 in. long, set upright on the holes, to take both heat 

 and steam up to the surface of the bed among the leaves, which I find very 

 congenial to the growth of cucumbers and other plants, p j), the upright 

 tubes or pipes, with lids to cover them when the steam is not required ; and 



