SASH-BED CONSTRUCTION 17 



purposes and give more or less satisfactory 

 results. Directions for making will be found 

 in Chapter VII. 



The Pit. As most hotbeds are heated by 

 fermenting manure, a necessary part is a pit 

 of some depth in which it may be placed. 

 This pit may be lined with boards, plank, 

 brick, stone or concrete, the latter being the 

 most satisfactory. Cypress, cedar, chestnut 

 and black locust are the most durable, moder- 

 ate price woods for this purpose. For data 

 on concrete construction see Chapter XV. 



The depth of the pit is determined by: (i) 

 The severity of the climate and (2) the kind 

 of plants to be grown. As more heat is pro- 

 duced for a longer time from a deep pit of 

 manure than from a shallow one, it is evident 

 that in cold climates and for plants requir- 

 ing considerable heat, such as tomatoes and 

 peppers, the pit must be deeper than in 

 warmer climates, or for plants like cabbage 

 or cauliflower which may be grown at lower 

 temperatures. For starting early vegetable 

 plants in late February or early March in 

 the north, 24 inches of manure will be re- 

 quired, whereas in milder climates, or later 

 in the season, 12 to 18 inches will be suffi- 



