MARKET GARDENING UNDER GLASS. 95 



entailing a great amount of manual labor, were expen- 

 sive, the cost, if taken into account, being often greater 

 than the value of the articles produced. Every reading 

 gardener knows that lettuce, asparagus, radish and 

 cucumbers have, for a century, been grown during win- 

 ter by bottom heat in glass covered hotbeds or in cold 

 frames, which slow methods are in use yet by private 

 gardeners "for home consumption ; but with the commer- 

 cial market gardener, who aims for the largest net re- 

 turns from his capital and labor, the old style hotbed 

 and cold frame no longer answer the purpose, for they 

 are expensive, as compared with returns, and do not 

 enable him to meet the enormously increased demand 

 for crisp winter-grown vegetables. In changing from 

 the old to the present system, mistakes were made in 

 the construction of the early forcing-houses, which time 

 and practical experience have modified and corrected. 

 Accordingly, such structures, buiit during the last 

 eight or ten years, are very different in appearance and 

 interior arrangements from those erected a dozen years 

 ago. At that time the ordinary greenhouse form was 

 imitated in constructing vegetable forcing houses. These 

 were usually built eleven feet wide and as long as neces- 

 sary, with side walls four feet high, the top roofed with 

 movable sashes three by six feet. In such houses there 

 were two tables three and one-half feet high running 

 the whole length, with a narrow passage-way in the cen- 

 ter. On these wooden tables, or benches, prepared soil, 

 to a depth of twelve to fourteen inches, was placed, and 

 made ready for the process of culture. The heating was 

 done by hot water, the same as now. The water used 

 was lifted by hand- worked force-pumps, and applied 

 sometimes by hose, but generally by the expensive sys- 

 tem of hand-pots, entailing a great amount of labor, a 

 slow and expensive method compared with the system 

 now practiced. 



