CHAPTER V. 
FROM FRAME TO FORCING HOUSE. 
The next step upward in the art of winter gardening, 
when cold frames and hot beds no longer fully meet the 
requirements of the cultivator, is the construction of a steam- 
heated or water-heated forcing house, using the same or 
similar sashes as those employed on the frames and hot beds. 
The advantage of the sash-covered house (as compared 
to frames) is that it enables the gardener to work under 
INTERIOR VIEW OF LOUIS REICHNER’S SASH-COVERED FORCING HOUSE, 
PHILADELPHIA, SHOWING CAULIFLOWER AND RADISH CROPS. 
cover; that he can reach his plants without exposing them 
to the weather ; and that the temperature can be better con- 
trolled. The element of economy is also to be considered, for 
while the sashes will cover no more ground space on a forc- 
ing house than they formerly covered on the frames, yet a 
more rapid crop rotation can be secured by the greenhouse, 
as compared to the more primitive plan, and the gardener’s 
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