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. 
