114 GREENHOUSES 



again and then apply boiled linseed oil to 

 both sides of the paper and dry again in a 

 warm place. 



(2) Dissolve 1 24 pounds of soap in a quart 

 of water; in another quart dissolve i/^ ounces 

 of gum arabic and 5 ounces of glue. Mix 

 the two liquids, warm, and soak the paper, 

 hanging it up to dry. Used mostly for 

 paper. 



(3) Take 3 pints pure linseed oil, I ounce 

 sugar of lead, 4 ounces of white resin. Grind, 

 and mix the sugar of lead in a little oil, then 

 add the other materials and heat in a kettle. 

 Apply hot with brush. Used for muslin. 



PAINTING 



Probably few other structures require as 

 careful or as frequent painting as do green- 

 houses. This is due: First, to the moist con- 

 dition of the air in the house, which favors 

 the decay of the wood; and second, to the dif- 

 ference in temperature between the outside 

 and inside of the house, which often causes 

 excessive contraction and expansion of the 

 structural material. It is especially important 

 that all joints in the framework be thorough- 

 ly coated when they are put together, and 

 that they be well painted in order to prevent 



