GLAZING AND PAINTING 113 



Substitutes for Glass. On hot beds and 

 coldframes and sometimes on temporary 

 greenhouses, some transparent material 

 other than glass is used. The reason for this 

 is that glass is both expensive and heavy to 

 handle. The most common substitutes are 

 cloth and paper treated so as to make them 

 waterproof and semi-transparent. Some- 

 times a firm but lightweight white cotton 

 cloth is used with no treatment, but it does 

 not admit light enough to permit satisfactory 

 growth of plants for any length of time. 



Paper can seldom be used for more than 

 one year. Cloth may, with care, be used for 

 several seasons. The best results are secured 

 by stretching the cloth or paper on rigid 

 frames or sash on which wires have been 

 drawn tightly across at frequent intervals to 

 serve as supports. The author has had good 

 success by simply painting the cloth or pa- 

 per, after stretching it over the frames, with 

 pure, light, boiled linseed oil. Bailey, in the 

 "Farm and Garden Rule Book," gives the fol- 

 lowing recipes: 



(i) Paste stout, but thin Manilla wrap- 

 ping-paper on the frames. Dry in a warm 

 place and then wipe the paper with a damp 

 sponge to cause it to stretch evenly. Dry 



