vi PREFACE 



mathematical knowledge is required, the work is such as may safely be 

 left by all but the more advanced student of the subject. 



In the section devoted to Hydraulic Machinery, it has not been 

 attempted to dt-al in any way exhaustively with the subject, and only 

 such machines have been illustrated or described as are typical of their 

 class, represent good modern design, and illustrate some definite principle 

 of construction. For many of these illustrations the Author is indebted 

 to tli' manufacturers, and while reference has been made to these in the 

 text, he would take this opportunity of thanking them collectively for the 

 help which they have so courteously tendered. 



&e was essential, reference has been freely made to the minutes of the 



dings of the various English and American societies, and to the 



English and German technical press, as well as to standard works on 



the subject. Of these the Author is particularly indebted to the Councils 



of the Institution of Civil Engineers, the Institution of Mechanical 



Engineers, the American Society of Civil Engineers, the Zcit&chiiJ't de* 



ms ilrHtwhfi- liHjcnit'nre, The Engineer, and Engineering. 



The greatest debt of all is, however, owing to the teachings and pub- 

 lished papers of his old professor arid some time chief, Osborne Reynolds. 

 Old students of the Professor will readily recognise to what extent any 

 slight merit which the book may possess is due, directly or indirectly, 

 to the influence of one to whom the science of Hydraulics owes so much. 



In conclusion the Author would tender his thanks to Mr. S. Chapman, 

 to Mr. E. Magson, and to Mr. C. H. Lander and Mr. F. Pickford, of the 

 Manchester University, each of whom has revised a portion of the proofs 

 and to whose kindly criticism and suggestion the book owes much. 



A. H. GIBSON. 



MANCHESTER, 



Ftiruary, 1908. 



