GLASS STRUCTURES 



101 



as to allow a person to go inside to do all the work of caring 

 for the plants. Fig. 37 shows the general plan of the house. 

 The size is 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 desired. To receive the most 

 sunlight the house should extend north and south ; the light 

 will then strike both sides of the plants. The south end 

 of the house is glazed from the surface of the bed up to 



Fig. 38. Sectional view of hotbed greenhouse. 



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 

 sloping as desired. 



"The heat is furnished by two to three feet of well-pre- 

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

 soil. The sashes are fastened to the rafters by screws 

 which prevents their being lifted by heavy winds and at 

 the same time allows them to be removed very easily when 



