106 VEGETABLE GARDENING 



156. The frame. The frame may be made of wood, 

 concrete, brick or stone. The most common material is 

 wood, although concrete is more durable. Of the woods, 

 locust, cedar and chestnut make the most durable frames. 

 A common plan is to use either locust or cedar for the 

 posts, and chestnut or other less durable woods for the 

 sides and crossbars. The frame may be of any desired 

 length, and wide enough to accommodate the sash. That 

 is, the width of the frame at the top should be about YZ 

 inch less than the length of the sash. 



The upper or north side of the frame should be 6 inches 

 higher than the lower or south side, in order to give the 

 proper slope. This can be easily accomplished by using 

 boards of 6 and 12-inch widths. Usually one 6-inch and 

 two 12-inch boards or planks are sufficient for the upper 

 side of the pit, and two i2-:nch pieces for the lower side* 

 the boards should always extend to the bottom of the 

 pit. The posts should be made of 2x4-inch lumber, or 

 heavier. It is usually necessary to remove some soil at 

 the sides of the pit where the posts are to be placed. The 

 best frame will be made if the boards are not more than 

 12 feet long, and posts driven at the ends and midway 

 between. 



Crossbars or slides are not always provided, but they 

 possess so many advantages that frames should seldom 

 be made without them. A 2x3-inch piece is about the 

 right size, and should be sound and surfaced on the upper 

 side. Some gardeners prefer a ^2-inch strip in the middle 

 of each crosspiece to prevent binding of the sash a pro- 

 vision that is well worth while making. The sash can 

 then be handled with much less annoyance. 



When placing the crossbars, great care should be ex- 

 ercised, for if they are too close together the sash will 

 bind and greatly annoy the attendant. If the sash are 

 3 feet wide, the distance from center to center of the 

 crossbars should be at least */2 inch more than 3 feet, 



