PROPAGATING HOUSES AND PITS. 1 9 



Tydaeas, and even for selected vegetables for seed purposes, 

 such as Carrots, Beet, Potatoes, Parsnips, Salsify, and many 

 others, The walls of the cellar are sloped inwards buttress- 

 like, so as to better resist the pressure of the soil from without ; 

 but, if .preferable, the walls can be carried down straight, and 

 buttresses formed at intervals. The roof of the house is 

 shaded when necessary by canvas rollers (a a) these being 



Propagating House with Cellar beneath in which to store Dahlias, Mirabilis, 

 and other Tubers. 



rolled up under the terminal coping by cords which work over 

 pulleys 8 inches in diameter fixed at the ends of the rollers. 

 The outer ventilators are shown at b b, and through these air is 

 admitted into the chambers beneath the stage through which 

 the hot-water pipes are conducted for bottom-heat ; while 

 through the valves at c c the heated air can be admitted into 

 the atmosphere of the house, the heated air of which escapes 

 through the ventilator at d, over which a sheet of wire gauze 



