56 ON THE GROWTH OF THE CUCUMBER 



turf, &c., should be two feet six inches from 

 the ground; thus leaving a space of about 

 a foot above in front between the trellis 

 and the mould, and at the back two feet. 

 The soil being raised in the centre to facilitate 

 the escape of the heat from the sides into the 

 pit, and to draw off the water as previously 

 remarked, it will be one foot, or rather more, 

 under the trellis there. The space between the 

 earth and glass will contain as much heated air 



O 



as can possibly be required, however cold and 

 severe the weather may be. I have used less 

 depth of wood and soil, in order to have more 

 room between the soil and the glass ; but found 

 it caused too dry a heat at top, and that, in 

 consequence, the pit was obliged to be continu- 

 ally sprinkled with water, particularly the walls. 

 The seed proving, time of sowing, pot treat- 

 ment, soil, and seed-bed, have been explained 

 in the previous chapters ; and the only point 

 now to be treated on is the raising of plants for 

 the pit. These plants are not to be stopped, as 



