SCIENCE IN THE INDUSTRIAL WORLD 



stored, so that the matter of storage space alone be- 

 comes an important factor. 



THE INTRODUCTION OF PROCESS WORK 



In all the methods of reproducing pictures that have 

 been described so far, the artistic skill of the engraver 

 or lithographer has played an important part. Any 

 workman to be successful in producing illustrations by 

 means of any of these methods must not only have 

 acquired a certain degree of perfection in mechanical 

 skill, but also have considerable artistic ability. As 

 a combination of these two qualities is rarely found in 

 the individual who has chosen engraving as a calling, 

 it followed that good reproductions of pictures which 

 really interpret the work of the artist satisfactorily, 

 were only produced by a limited number of high- 

 priced workmen. 



On the discovery of photography by Daguerre, 

 whereby chemical rather than mechanical means were 

 used for reproducing representations of natural ob- 

 jects with more fidelity than by any method previously 

 known, attention was directed to applying this new 

 process to the reproduction of pictures. For many 

 years these efforts were not successful, but about the 

 beginning of the last quarter of the nineteenth century, 

 it was discovered that a mixture of albumin and bi- 

 chromate of potash could be hardened by exposure to 

 light, this hardening varying according to the intensity 

 of the light, the resulting hardened substance not 

 being acted upon readily by acids. 



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