440 



FOREST PRODUCTS 



ness. There are no standard methods of grading requirements for either 

 the thickness or quality among the various companies. All cork after 

 manufacture is sold on the basis of samples. The slabs of cork to be 

 shipped are then baled in hydraulic presses, and tied iip with wire. 



FIG. 118. Baling cork after boiling, scraping, grading and trimming. Considerable cork is 

 shipped to this country in this form. Photograph taken at a large cork factory in Seville, 

 Spain. 



UTILIZATION OF CORK 



Cork possesses a number of properties which distinguish it and render 

 it adaptable for use in a great diversity of ways. Its principal features 

 are: 



1. Lightness in weight. 



2. Compressibility and elasticity. 



3. Comparative imperviousness to liquids as well as to air. 



4. Compa r ative strength and durability in relation to its other 

 properties. 



5. Low conductivity of heat. 



The combination of these characteristics renders it invaluable for 

 many specialized purposes. Its low specific gravity combined with its 



