94 BOAKD OF AGRICULTURE. 



has had uniform success in raising lettuce by fire heat. And I 

 am glad to be able to add, that Mr. Morse does not use 

 bottom heat. His house is a single roof, twenty-four feet 

 wide, facing south, at the ordinary flat angle of frames. A 

 large amount of ventilation is secured at the front and top. A 

 four-inch water-pipe runs along the front, and a flow-and- 

 return pipe rims up and down each of the two narrow sunken 

 walks which divide the house. Whatever difficulties of drip, 

 and of snow, and of ventilation may attend this form, yet it is 

 certain that excellent crops have here been produced in mid- 

 winter at very much less expense than by the old method. 



A style of houses which has come into general use and is 

 commonly known as the ridge and furrow (though entirely 

 distinct from the form so called and applied by Sir J. Paxton 

 at Chatsworth) is too well known to require a description. 

 These houses have been usually constructed of sashes six feet 

 in length, and providing for ventilation by merely raising or 

 tilting as many sashes as may be found necessary. This 

 method is much more expensive, and it is by no means as 

 tight as a fixed roof with simple sash-bars. For this reason 

 sashes are not to be recommended, except in case of crops 

 which require full exposure to the air. It is apparent at a 

 glance that this form has many excellences. The entire 

 expanse of glass, however large it may be, is yet divided into 

 small sections about ten feet wide, thus avoiding the arid and 

 chilly draughts which are found in large houses. The heat in 

 these low and separate compartments is humid, genial and 

 uniform. The plants are near to the glass, accessible with the 

 utmost ease, and the head-room is obtained with economy of 

 space at the apex of the ridge. The houses are designed to 

 be low, the ridge not being in any case more than seven feet 

 above the ground surface. It is evident that there is economy 

 in the construction of a compact block of houses with but four 

 outside walls, however extended the range may be. A still 

 more important advantage results, that but four sides are 

 exposed to the cold ; the intermediate sections are flanked by 

 a tropical rather than an arctic temperature. Different opin- 

 ions are expressed as to the true position of these houses, 

 whether the ridges should run east and west, or north and 

 south. The question can be answered only by determining 



