104 VEGETABLE GARDENING 



quarter. To this we might add one known as the side-hill 

 greenhouse. This is cheaper to build, but rather hard to 

 manage, from the fact that it is on uneven ground. The 

 lean-to house is usually placed next a building as a lean-to, 

 but is not as satisfactory as the even-span or the three- 

 quarter-span house. Usually the even-span house should 

 run north and south and the three-quarter-span east and 

 west to make the best use of sunlight. But this is not so 

 important if part iron construction is used, which allows 

 more light to get into the house. 



Materials. Greenhouses are constructed of cypress, 

 concrete, and iron. The all-iron construction is probably 

 not as serviceable, especially in the north, as the semi-iron 

 or the wood. It costs one- third to one-half more to build 

 in the first place and is more subject to weather changes, 

 than the wood or the semi-iron house. Glass should be of 

 double strength. The smaller single strength is more 

 imperfect and more apt to break.- It is well to use as large 

 glass as possible, since on account of fewer sash bars more 

 light is let into the greenhouse. Sizes ranging from 14x16 

 to 20x24 inches are used. 



The houses should be well painted when put up and 

 frequently painted thereafter. Provision should be made 

 for plenty of ventilation by installing some simple and 

 effective system. The size of the house will vary with the 

 use it is put to and the amount to be invested. They are 

 constructed from 18 to 30 feet wide and may be of indef- 

 inite length. The crop grown will determine the kind 

 and location of benches. 



Hot water is perhaps the best heat, but is often too 

 expensive, and so steam is used very generally. 



A very cheap yet serviceable greenhouse is described 

 in "How to Make the Garden Pay," and the publishers 



