MARKET GARDEI^TKG UNDER GLASS. Ill 



named, and well grown, with crisp, solid heads, may 

 sell at wholesale at from seventy-five cents to a dollar a 

 dozen, or from four to five dollars a barrel. The third 

 crop sells for less, say from fifty to seventy-five cents a 

 dozen. Clean, perforated barrels are best for shipping 

 lettuce, and when carefully packed the lettuce will keep 

 fresh for a week. There are times when general business 

 is dull and prices fall below these figures, and, on the 

 other hand, times when there is a good demand; then 

 prices are higher than those named. 



The house under system No. 4 may be of the same 

 construction as either Nos. 1, 2 and 3, but differs from 

 them in being without any apparatus for heating. It 

 may, therefore, be properly termed a sun house. It is 

 an improvement upon the ^^cold frame" long used for 

 growing vegetables for early winter and spring use. By 

 the old system of cold frames, only one crop of lettuce 

 could be grown. The plants were set late in autumn, 

 and the crop so handled as to be ready for market early 

 the following spring, a month or six weeks before crops 

 are produced in the open garden. But now, in sun 

 houses, modern practical gardeners have a new and im- 

 proved method of raising lettuce under glass without 

 artificial heat. This new method, although more expen- 

 sive for the first outlay and construction, has, after sev- 

 eral years of experience, proved to be more certain and 

 profitable in the long run than houses provided with 

 artificial heat, and it is asserted, by those who have such 

 houses in full operation, that, considering the difference 

 in the first cost, they are more profitable than those 

 equipped with the most modern heating apparatus. In 

 these houses three crops of lettuce can be grown in a 

 season, while with those furnished with artificial heat 

 only two, often only one, additional crop can be grown 

 with profit. 



Sun houses may be built on the same plan and of 

 the same dimensions as any of the forcing houses de- 



