CHAPTER IX. 



GLASS STRUCTURES. 



Glass structures are becoming- more numerous each sea- 

 son for the purpose of raising vegetables and flowers, and are 

 destined to continue to increase in use as the wealth of the 

 country increases. They are referred to here under the head 

 of cold frames, hotbeds and greenhouses. 



Cold Frames. — The term cold frame is applied to frames 

 covered with glass and used to protect plants in winter, or 

 for forwarding them without any heat other than that derived 

 from the sun. It is the simplest form of glass structure. 



Figure 23.— Movable frame which may be stored out of the way in the summer. 

 It is generally made of one inch boards and is very convenient for those 

 using only a few sashes. 



They are generally made 4| or 6 feet wide and of an ylength 

 or depth which convenience may suggest. The sashes for 

 covering them are generally 4x4! feet or 3x6 feet in size. For 

 location, select a place near to water and the house, prefer- 

 ably sloping to the south and well protected on the north, and 

 west by buildings, trees, etc. If there is no protection on the 

 north and west, a tight board fence six feet high will answer 

 the purpose and is very desirable. In making the bed the 

 following are requisites: enough 2x12 in. plank to go the 

 length of the north side and the same length of 2x6 in. plank 

 for the south side of the bed and 2x4 in. stakes, two or more 

 feet long, for each corner and to support the sides firmly in 



