PREFACE. 



THE systematic testing of the materials used in all 

 classes of engineering work is becoming so general that 

 little apology is needed for the existence of this book ; 

 ,unl it is hoped that it will be found helpful, both to 

 young engineers, who have opportunities of using the 

 various appliances described, and also to older men who 

 have, in the ordinary course of their practice, to make 

 use of some of the materials referred to. 



Though there may be a slight want of homogeneity in 

 some parts of the book, the author has tried to place the 

 chapters in proper sequence, and take the reader from the 

 early mechanical principles involved in testing work, 

 through the description of the appliances and methods 

 used, to standard results of tests, both general and for 

 specific materials. Too much detail has not been 

 attempted in describing the testing operations ; a com- 

 plete working knowledge can only be obtained by 

 intimate personal contact with the work and a consider- 

 able amount of actual practice. 



Reference has been made to most of the publications 

 relating to the subject, and the author desires to 

 acknowledge his indebtedness, and express his sincere 

 thanks, for much valuable help gained from Prof. Unwin's 

 " Testing of Materials of Construction," as well as from 

 the two standard works on the same subject by Profs. 

 Thurston and Johnson ; to Mr. J. Hartley Wick steed, 

 of Leeds, for much helpful advice ; to Prof. Ewing of 

 Cambridge, my friend, Mr. F. G rover of Leeds, Prof. 

 Stanton of Bristol, Dr. Wilson of Owens College, and 



