84 GENERAL ADVICE 



would be better to make a forcing -house. Hot- 

 beds may be heated, however, with hot air flues 

 with very good results. A home-made brick fur- 

 nace may be constructed in a pit at one end of 

 the run and underneath a shed, and the smoke 

 and hot air, instead of being carried directly up- 

 wards, is carried through a slightly rising hori- 

 zontal pipe which runs underneath the beds. For 

 some distance from the furnace, this flue may be 

 made of brick or unverified sewer pipe, but stove- 

 pipe may be used for the greater part of the run. 

 The chimney is ordinarily at the farther end of 

 the run of beds. It should be high, in order to 

 secure a good draft. If the run of beds is long, 

 there should be a rise in the underlying pipe of at 

 least one foot in twenty -five. The greater the rise 

 in this pipe, the more perfect will be the draft. 

 If the runs are not too long, the underlying pipe 

 may return underneath the beds and enter a 

 chimney directly over the back end of the fur- 

 nace, and such a chimney, being warmed from the 

 furnace, will ordinarily have an excellent draft. 

 The underlying pipe should occupy a free space 

 or pit beneath the beds, and whenever it lies near 

 to the floor of the bed or is very hot, it should be 

 covered with asbestos cloth. While such flue- 

 heated hotbeds may be eminently successful, it 

 may nevertheless be said, as a general statement, 

 that whenever such trouble and expense are incurred 

 it is better to make a forcing -house. Full direc- 



