22 VEGETABLE FORCING 



cucumbers are produced to a considerable extent in mid- 

 winter. Fig. 3 shows a hillside three-quarter-span house 

 at New Castle, Pa. The house is 120 feet wide and 600 

 feet long. The soil for a distance of 70 feet from the 

 south wall rises three inches to the foot, while the 50 feet 

 of ground on the north side is practically level. This 

 mammoth structure has been highly satisfactory for the 

 growing of lettuce, cucumbers and tomatoes. 



Two-third-span houses are used occasionally. Near 

 Chicago and in other western sections what is known as 

 the "standard house" meets with favor. The houses are 

 27 feet wide and they run east and west. The roof-bars 

 on the north side are 16 feet long, and on the south side 

 14 feet, so that the northern slope is the longer. This is 

 a radical departure from the three-quarter-span houses of 

 the East. Perhaps the sole purpose of the 14 and 16-foot 

 slopes is to avoid shading as much as possible in these 

 connected houses, for the ridge runs slightly south of the 

 center of the house, and the shadow cast by it during the 

 short days of winter falls in line with the shadow of the 

 north gutter; therefore, only one shadow is cast on the 

 plants in the next house to the north. 



It will now be seen that the form of a house is largely 

 a matter of personal preference, and from the results of 

 successful growers it cannot be said that this or that par- 

 ticular type is best adapted to vegetable forcing. Any 

 form of modern construction will, with good management, 

 produce satisfactory crops. 



Wood construction. In the early greenhouses all parts 

 of the frame were made of wood, but in recent years iron 

 and concrete have been substituted, wherever possible, 

 because of their greater durability. If for any reason it 

 seems desirable to use wood throughout, only the most 

 durable should be selected. Cypress is now employed 

 almost exclusively, and with proper care it will last for 

 many years. 



