PRESENT DAY STATUS OF THE ART. 53 



work of obtaining the residuary resistances for the wide range of speeds and co- 

 efficients that is given in Figs. 81-120 is in itself a gigantic task and for which the 

 profession all over the world is indebted in no small measure to the author and to 

 the United States Government, in whose tank it was so largely obtained. 



It can safely be said that this book marks an epoch in the methods in practical 

 use for desigpiing and powering ships. Shipbuilders and owners are now fully alive 

 to the value of the tank and are keen to take advantage of all it can teach them, to 

 their no small benefit in coal bills and better service. 



Since beginning this paper — in fact, very near the ending of it — Mr. G. S. 

 Baker's new work on ship propulsion has become available in this country. Mr. 

 Baker summarized the present status of tank work and our knowledge of this 

 whole subject in a very able and clear manner. He uses, in the main, the "con- 

 stant" system of notation, which is perhaps not as much used on this side of the At- 

 lantic as on the other, and his book is a most valuable contribution to the litera- 

 ture on the subject, the main results of recent experimentation being carefully 

 gathered together and presented in one volume, very much my own purpose in 

 writing this paper. As in much other recently published matter, the full-cargo ship 

 receives considerable attention in Mr. Baker's book. 



The chapter on canal towage contains information not generally available in 

 such useful form. These two books set forth our knowledge on the subject so 

 clearly and well that the question may be asked as to the necessity of quoting at 

 length the papers, etc., listed at the close of this paper. To study the steps leading 

 up to their production and the work done by these and other investigators will re- 

 pay the men responsible for the dimensions and lines of our ships, both naval and 

 mercantile. It is largely in the hope that our younger members will be helped in 

 their researches by this brief review of present day knowledge that this paper has 

 been prepared. The author is well aware that no new discoveries are set forth 

 herein, but trusts that, in spite of that fact, the science of ship propulsion will be 

 benefited by this addition to our Transactions. 



It will be noted that this paper only covers the literature of our own language 

 on this subject. At first sight this appears unfortunate and there are, doubtless, 

 many undiscovered gems of knowledge tucked away in foreign works. In the 

 main, however, the work of foreign investigators is summarized in the books and 

 papers listed, and as the same are there acknowledged, no injustice is done the men 

 whose work is thus only indirectly referred to. 



The Society was founded in 1893 ^^^ the 1915 volume will be No. 23. In 

 searching for papers it frequently happens that much time is lost through lack of 

 a comprehensive index, therefore I would strongly urge that the Transactions be 

 indexed, such index to be sold to members at cost price. It would be necessary to 

 keep the index up to date, but if the work were kept up each year to prevent undue 

 accumulation, supplementary indices could be issued every three or four years and 

 the whole combined every ten years or so, or as the stock of the main index was ex- 

 hausted. 



