Salad Culture. 239 



The glasses are nearly sixteen inches in diameter, and about as 

 much in height. For the winter work they are placed on a sloping 

 spot with a sunny aspect, or the ground is thrown into beds wide 

 enough to accommodate three lines of glasses. In early autumn 

 these beds are made and the plants placed upon them, so that they 

 can be readily covered by the bell glasses when the time comes that 

 growth is checked in the open air. It should be added that the 

 ground chosen is thoroughly rich, light, and well and deeply stirred, 

 and the lettuces are sown at intervals of a fortnight or so, so as to 

 secure a succession, and to provide for the wants of the various 

 kinds. The plants put out in September for the early and mid- 

 autumn supply may not require to be covered if the weather be 

 fine; and if they do, the glasses are a little tilted up as before de- 



FlG. 72. 



scribed. But when the sun begins to fail and the cold rains to 

 check growth, about the end of Octofeer, then the crop to be cut in 

 the following month must be covered ; and when towards Christ- 

 mas the frost begins to take hold of the ground, the glasses must 

 be firmly pressed down, and a deposit of leaves and litter placed' 

 among and around them. Thus, while all around is at rest in the 

 grip of ice, the plants will be kept perfectly free from frost, while 

 receiving abundant light from above, and growing as fresh as April 

 leaves. Of course a deeper layer of this surrounding litter will be 

 necessary in case of severe frost than is so in early winter. Cover- 

 ing them a little more than half-way up with a rather compact body 

 of leaves and litter, effectually secures them from sharp frosts. 

 When very severe frosts occur, mats made of straw are spread over 

 the tops of the glasses ; and should heavy falls of snow occur while 



