10 FRUIT TREES IN POTS [ch. 



the rafters, the size of glass and glazing, etc., the 

 same as advised for the house 18 ft. wide. 



The last, but by no means the least, point to 

 decide is the top ventilation of the house. I 

 strongly advocate plenty of top ventilation, and 

 recommend a ventilator running the whole length 

 of the house on both sides alternately, as used by 

 our leading florists and market gardeners in their 

 houses. There is a great advantage in having 

 ventilators on both sides of a house, for in the 

 event of cold or strong winds blowing from the 

 north, the ventilators on the south side can be 

 utilized, or vice versa. There is also the means of 

 introducing more air when required. 



In this house 24 ft. wide, etc., there should be 

 double instead of single doors at each end, and 

 each door should be 2| ft. wide, thus giving a space 

 5 ft. instead of 3. The height of the doors should 

 be the same as in the plan. 



Cross-tie irons, of the same dimensions as those 

 in the plan, should be used, as they will serve to 

 keep the roof of house in position. 



Where more than one " span-roof house " is 

 required, each house should be an independent 

 house, and not a succession of what is commonly 

 known as the " ridge and gutter " houses, as these 

 houses are not well adapted for growing " fruit 

 trees " in pots. This matter should be strictly 



