FORCING PITS OR GREEX-IIOUSES. 59 



able sash is elevated, to admit air, by an iron bar, 

 15 inches long, attached to the sash by a staple ; in- 

 to this bar is punched three holes, so to regulate the 

 admission of the air as required. When the sash is 

 shut down, the bar is hooked on to a pin which ■ se- 

 cures it in place, so that the sash cannot be moved by 

 wind. I am thus particular in describing what may seem 

 a simple matter ; but this system of airing is not common, 

 and we made some stupid blunders before we hit on our 

 present plan, which is cheap, simple, and very effective. 

 The movable sash is not hinged at the bottom, but is held 

 in place by two small plates of iron screwed on the gutter 

 plate. The ridge-poles are cut out of the shape shown 

 at I, and the sashes lie on the shoulder. The interior 

 arrangement of the pits will be easily understood by the 

 end section. G, shows the bench or table as it is complet- 

 ed; this shows the boxing-in of the pipes, (J9), to give 

 " bottom heat " to the cuttings, seeds, or plants, that are 

 placed on the bench, but on the sides of the bench, along 

 the walk, one plank is hinged throughout the house, so 

 that it may be let down when required, and permit the es- 

 cape of heat into the pit. The walks through the house, 

 (iT), are 2 feet wide. A brick shed, (A), covers the 

 boiler pit, (F), and is attached to the north end of the 

 pits. Besides breaking the wind at this vulnerable point, 

 we find this shed a most excellent place for many purposes, 

 as it is kept from freezing by the heat that escapes from 

 the boiler pit, winch would otherwise be lost. This heat 

 inay be rendered to a very profitable account in forcing 

 Mushrooms or Rhubarb, if desired for that purpose. 

 The system of attaching three pits together, if not new 



