WILEY ENGINEERING SERIES 



THE Wiley Engineering Series will embrace books devoted 

 to single subjects. The object of the series is to place in the 

 hands of the practicing engineer all the essential information 

 regarding the particular subject in which he may bs in- 

 terested. Extraneous topics are excluded, and the contents 

 of each hook are confined to the field indicated by its title. 



It has been considered advisable to make these books 

 manuals of practice, rather than theoretical discussions of the 

 subjects treated. The theory is fully discussed in text-books, 

 hence the engineer who has previously mastered it there, is, 

 as a rule, more interested in the practice. The Wiley En- 

 gineering Series therefore will present the most approved 

 practice, with only such theoretical discussion as may be 

 necessary to elucidate such practice. 



