INTRODUCTORY PROCEEDINGS. xxxv 



Notwithstanding unfavorable legislation the shipyards in the United States have been 

 unusually active during the last twelve months, as will be seen from the following statement 

 of vessels under construction during this period. 



The statistics of the Department of Commerce show the following vessels imder con- 

 struction on July 1, 1915: — 



Merchant Vessels. Government Vessels. 



No. Tons. No. Tons. 



Seacoast yards 62 294,138 54 184,732 



Great Lakes and rivers yards. . 14 15,951 IS 6,058 



Totals 76 310,089 69 190,790 



No official records of contracts placed since that date are available, but it is- a fact that 

 at the present moment there is scarcely a building berth available either in the sea coast or 

 Lake yards, and that shipowners now ordering new tonnage will for the most part have to be 

 satisfied with delivery in 1917. It is interesting to note that a large proportion of these 

 new vessels are to be used in the carriage of oil in bulk. 



The main cause of this increase in shipbuilding may be laid to the European war, as 

 the withdrawal for many reasons of so large a proportion of the world's tonnage created a 

 condition most favorable to the shipowners in this country. Were it not for the harassing 

 legislation existing against shipowners and ship operators, no doubt much more capital would 

 have been attracted to the shipbuilding industry, but we should be thankful that the yards 

 are benefited to a very considerable degree. 



In marine engineering the use of fuel oil in place of coal is becoming more and more 

 general. The geared turbine, which has been used abroad successfully for many classes 

 of vessels, is now commencing to be used in this country also with pronounced success. 

 The use of the straight-drive turbine for high-speed vessels continues to be entirely 

 satisfactory. Electrical drive is being carefully investigated and developed, and the Navy 

 Department has lately specified one of the new battleships to be propelled in this manner. 



The Diesel engine continues to be largely used for submarines, but its general use has 

 not been greatly developed. The semi-Deisel or hot-bulb engine, approximating to the regu- 

 lar Diesel in efficiency, is commencing to be a strong competitor and is replacing steam in 

 many instances where the power to be installed is not excessive. 



As there are so many and such important papers to be read and discussed, I will not 

 further occupy your time, and will now proceed with the regular order of business. 



The President : — The first paper to be taken up at this session is No. 1, entitled "Aero- 

 dynamical Experiments upon a Yacht's Mainsail," by Prof. H. A. Everett, Member of the 

 Society. We will now have the paper. 



Professor H. A. Everett, Member: — Mr. President and members of the Society, as 

 this paper is rather brief, I will ask the indulgence of the Society if I read the major part of 

 it in extenso. 



