118 GREENHOUSES 



A general rule for determining the amount 

 required is as follows: Divide the number 

 of square feet of surface to be painted by 200, 

 the result will be the number of gallons of 

 liquid paint required to give two coats. 



Another is: Divide the number of square 

 feet by 18. The result is the number of 

 pounds of pure, ground, white lead necessary 

 for three coats. 



Shading. During the summer the heat 

 becomes so intense in a greenhouse that some 

 shade must be given if plants are to be grown 

 satisfactorily. This may be accomplished by 

 the use of muslin curtains in the inside of 

 the house or by lath screens laid upon the 

 roof. The most common method in com- 

 mercial houses is to apply some kind of a 

 coating to the outside of the glass which will 

 be washed off by the late fall rains. Some 

 form of whitewash is most satisfactory. 



The author prefers a wash made of fresh- 

 ly-slaked stone lime and water, to which is 

 added one part of common salt to four parts 

 of lime. The salt is added after the lime is 

 slaked. This is then strained and applied 

 with a spray pump. It is usually necessary 

 to apply this two and often three times dur- 



