vi GENERAL PREFACE 



the orthodox textbook manner, not only to make the treat- 

 ment original, but also to appeal to the very large class of 

 readers already possessing good textbooks, of which there 

 are quite sufficient. The books should also be found useful 

 by men of affairs having no special technical knowledge, but 

 who may require from time to time to refer to technical 

 matters in a book of moderate compass, with references to 

 the large standard works for fuller details on special points 

 if required. 



To the advanced student the books should be especially 

 valuable. His mind is often crammed with the hard facts 

 and details of his subject which crowd out the power of 

 realizing the industry as a whole. These books are intended 

 to remedy such a state of affairs. While recapitulating the 

 essential basic facts, they will aim at presenting the reality 

 of the living industry. It has long been a drawback of our 

 technical education that the college graduate, on commencing 

 his industrial career, is positively handicapped by his 

 academic knowledge because of his lack of information on 

 current industrial conditions. A book giving a compre- 

 hensive survey of the industry can be of very material 

 assistance to the student as an adjunct to his ordinary text- 

 books, and this is one of the chief objects of the present 

 series. Those actually engaged in the industry who have 

 specialized in rather narrow limits will probably find these 

 books more readable than the larger textbooks when they 

 wish to refresh their memories in regard to branches of the 

 subject with which they are not immediately concerned. 



The volume will also serve as a guide to the standard 

 literature of the subject, and prove of value to the con- 

 sultant, so that, having obtained a comprehensive view of 

 the whole industry, he can go at once to the proper 

 authorities for more elaborate information on special points, 

 and thus save a couple of days spent in hunting through the 

 libraries of scientific societies. 



As far as this country is concerned, it is believed that 

 the general scheme of this series of handbooks is unique, 

 and it is confidently hoped that it will supply mental 



