68 VEGETABLE GARDENING. 



12x24 feet. The roof consists of sixteen sashes, each 3x6 feet. 

 Any number of sashes may be used according- to the size of 

 the house. To receive the most sunlight, the house should ex- 

 tend north and south: the light will then strike both sides 



Sc<vle»in:$t. 



Figure 28.— Sectional view of hotbed greenhouse. 

 of the plants. The south end of the house is glazed from the 

 surface of the bed up to the rafters. It is not necessary to 

 excavate the full depth of four feet, because the earth that is 

 thrown out can be used to bank up with on either side, making 

 a terrace as steep or as sloping as desired. 



The heat is furnished by two to three feet of well prepared 

 manure in each bed, over which is placed five inches of soil. 

 The sashes are fastened to the rafters by means of screws 

 which prevents their being lifted by heavy winds and at the 

 same time allows them to be removed very easily, when desired, 

 to replace soil or manure. Ventilation is provided for by 

 fastening one or more sashes with hinges at the bottom, so 

 they may be raised as high as necessary at the top. 



Many kinds of building material may be used in the con- 

 struction of the wall, beds, etc. Lumber is used in the build- 

 ing shown in the figure but brick or stone would be more dur- 

 able in the end, though it would add considerably to the first 

 cost. The posts are three feet apart, extend about two feet 



