WYKEHAM MA11TIN — : 



-UYPOCAUST-IIEATINO. 



11 



sufficiently set. Previously to the construction of the floor, as I 

 was obliged from local circumstances to place the fire and the 

 chimney on the same side of the house, I had constructed a flue, 

 nearly horizontal, for 7 or 8 feet across the house, in order that 

 the heat should be delivered nearly at the corner opposite to the 

 chimney. I was apprehensive that, without this precaution, the 

 heat might steal along the back wall and not circulate through 



the chamber ; I should otherwise have only taken the precaution 

 of making the floor thicker over the fire, by filling up the space 

 above it with concrete, or of leaving a vacuum between the cover- 

 ing of the fire-place and the floor, for a sufficient distance to 

 prevent the floor cracking or becoming too hot. The fire-place 

 consisted of an opening 23 inches wide and about 30 inches high, 

 built in fire-brick, the bottom consisting of the cast-iron bars 

 used for the fires by which hops are dried in my neighbourhood. 

 The opening can be closed by means of a piece of sheet iron hung 

 over a pulley by a chain with a balance weight, and in the chimney 

 there is also a damper. By these means it was intended, when 

 once the floor and chamber are heated, to make them part with 

 their heat very slowly, so that, excepting in the permanent cold 

 weather of the winter, a fire would only be needed for a portion 

 of the twenty-four hours, and until the middle of the autumn for 

 only a very limited portion. But in addition to the space below 

 the hothouse, the chamber was continued under the vine-border, 

 similarly supported on 9-inch pillars ; these were not of uniform 

 height, the outer chamber setting out with a height of 2 feet 

 6 inches, and dying away to 6 inches at about 11 feet from the 



