COLD FRAMES 361 



period, the greater depth is desirable. The pit is dug in 

 the fall before the ground freezes and protected with leaves 

 or manure during the winter. It should be of the same 

 width as the length of the sash and of any desired length, 

 and should extend east and west. The frame may be 

 made of wood, brick, or concrete. The north side of the 

 frame should be about six inches higher than the south 

 side, to give the bed the proper exposure. 



For hotbeds, fresh horse manure containing a large por- 

 tion of straw is preferred. This is stacked in a shed or 

 other protected spot in piles four to five feet wide and 

 about four feet high. After two or three days, these piles 

 should be forked over, and three or four days later shoveled 

 into the pit. The frame is also banked outside with 

 manure. In filling the pit, the manure should be placed 

 in successive layers of five or six inches and thoroughly 

 tamped down, especially along the sides of the frame. 

 From four to six inches of good soil is then spread over the 

 top. If a thermometer is thrust into the soil, it will be 

 noticed that the temperature rises considerably for a day 

 or two. After it has receded to about 80 Fahrenheit, the 

 bed is ready for use. 



Muskmelons, cucumbers, lettuce, tomatoes, and many 

 other vegetables may be started in the hotbed and later 

 transplanted to the field. Hotbeds are largely used for 

 growing and maturing such crops as radishes and lettuce. 

 In the fall, they are often used for maturing late crops. 



Cold Frames. A cold frame is even simpler than a hot- 

 bed, to which it is quite similar except that no bottom heat 

 is supplied, hence it is not necessary to dig a deep pit for 

 its construction. A cold frame is built on the surface of 

 the ground, using a twelve-inch plank for the upper side of 



