SCIENCE IN THE INDUSTRIAL WORLD 



thick, of a dark, blackish color, and may be worked with 

 the saw and chisel the same as ordinary boards. They 

 are only adapted to certain purposes, and are relatively 

 expensive as compared with common lumber. A very 

 common use of such boards is for the perforated seats 

 used in waiting-rooms. 



A more useful substance, and a much more familiar 

 one, is papier-mache, which has been used for various 

 purposes for something like a century. Ordinarily it is 

 made from waste paper, repulped and mixed with a 

 strong size of glue and paste, to which chalk, clay, or 

 lime is sometimes added. To make the finest papier- 

 mache, strips of specially made strong paper are 

 soaked in a strong size of paste and glue, molded into 

 any shape required, and dried in an oven. They are 

 then hardened by dipping in oil, trimmed, and japanned 

 or painted, and made into one of a thousand different 

 useful or ornamental articles, such as boxes, trays, 

 artists' lay-figures, picture frames, and mural decora- 

 tions. This substance is used also for certain kinds of 

 roofings, and is a very excellent floor-covering. 



The antithesis of these hard-paper products is the 

 chamois fiber, just referred to. This is made from the 

 long-fibered sulphite stock of the wood-pulp factory. 

 As this pulp passes through a set of special machines 

 the fibers are mangled and pulled about until the 

 resulting fabric is a soft, flexible, chamois-like sub- 

 stance. It is impervious to air, is a poor conductor of 

 heat and cold, and, as it wears fairly well, is sometimes 

 used for making undergarments. 



Obviously it would be useless to attempt even the 



