PREFACE 



IT is an old and true saying that " of making many books there is 

 no end," and this is especially true in regard to engineering treatises, 

 as each decade brings its improvements, and practices that are 

 in vogue one year are almost obsolete within a few years. To-day, 

 too, there is a great demand in the profession for books on practical 

 subjects, as it is only in this manner that the young man is able 

 to profit from the experience of his older brother. 



It is a singular fact that nearly every man feels that he is com- 

 petent to carry on a job of earth or rock excavation, yet there is 

 nothing more difficult than to do such work economically. Man 

 since prehistoric times has been digging into mother earth, yet 

 there is always something to learn regarding excavation work. 

 The last word will never be said on the subject. In this treatise 

 only one class of excavation is touched upon, namely, dredging. 



If one needs an excuse for offering to the profession this book, 

 it is found in the vast importance of dredging in our commercial 

 life. Not only are there millions upon millions of dollars invested 

 in dredging plants and outfits, but it has only been possible to con- 

 struct and use vessels of great tonnage, owing to, the wonderful 

 achievements of the dredge designers and the engineers and con- 

 tractors engaged in operating such machines. 



Then, too, great canals are constructed with the aid of dredges, 

 large areas of swamp lands are reclaimed for the use of man with 

 such machines, and precious metals are recovered from streams or 

 river bottoms with their aid. 



This treatise is written with a view of presenting the subject 

 in a concise and logical manner, so that it may be found useful 

 both to the man of experience and to the beginner or student. 

 Should it so prove the author will feel that his labor has not been 

 in vain. 



The thanks of the author are due Mr. Daniel J. Hauer for many 

 valuabla suggestions. Q p 



Manhattan College, September, 1911. 



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