MARKET GARDENING UNDER GLASS. 97 



plan No. 1, is thirty-one feet wide, outside measure, two 

 feet less inside, and two hundred and fifty feet long. The 

 house is set down in an excavation, partly below the sur- 

 face, the footwalks being thirty inches below the outside 

 level. The exterior walls, four feet high, are built of 

 brick, thirty inches below the surface and eighteen 

 inches above it on the outside. The top of these walls 

 is finished to receive a plate. * The top of the house is 

 a lean-to span with a hip-joint. The ridge-pole is eleven 

 feet above the floor, and jointed. The pine strips run- 

 ning from the plate to the ridge-pole are one and one- 

 half by two and one-half inches, made fast to a cross- 

 piece at the hip-joint and ridge-pole, and are ten inches 

 apart. Heavy French glass 8x10 is glazed on the out- 

 side of the strips. It is economy to use the best quality 

 of glass for this purpose. Every twelve feet on both 

 sides there is a hinged sash, running from the plate to 

 the hip-joint. By this means the house can be aired 

 when necessary, an operation of the utmost importance. 

 With this exception the roof structure is made fast, 

 avoiding the use of movable sashes entirely. The water, 

 falling upon the roof, is all saved and led by gutters into 

 a cistern at the end of the house, to be used for watering 

 the plants when needed. As the rain falling upon the 

 roof may not be sufficient, a well and pump are provided 

 to meet cases of emergency. There are three tables, or 

 beds, running the length of the house, and two narrow 

 passage-ways. The center bed, which is eighteen feet 

 wide, is made by erecting two parallel walls of brick, 

 running through the length of the house to within six 

 or eight feet of each end. These walls should be eight 

 inches thick and three and one-half feet high. In digging 

 the excavation for the house, the space designed for the 

 center bed may be left intact, excepting the removal of 

 the upper half. This block of natural soil is walled in, 

 forming a solid bed distinct from the side beds, which 

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