TEN THOUSAND DEADWEIGHT-TON TANKER. 



327 



fessor Bragg have just given us in the appendix to their paper is very interesting, because 

 it shows how httle that assumption was open to question. 



Admiral Taylor's remarks are to the effect that the propulsive efficiency curve would be 

 slightly higher if the model were towed again at the tank at a displacement corresponding 

 to that of the trial. We were unable to have that done, but I believe, as he says, that the 

 error involved in tliat slight correction is not material. 



Agreeable to my promise I am supplying the information requested by Professor Bragg 

 in his discussion at the meeting: 



Diameter piston rods 6j4 inches 



Clearances, Top % inch 



Bottom ^ inch 



Cut-ofI in inches 



Cut-off per cent of stroke 



Cut-off per cent o( stroke (mean). 



H. P. 



Top. 



38.9 

 76.4 



Bot. 



37.5 

 73.6 



75 



M. P. 



Top. 



38.8 

 76.2 



Bot. 



37.6 

 73.8 



75 



L. P. 



Top. 



37.4 

 73.4 



Bot. 



35.8 

 70.2 



71.8 



Lines — Length fore body, 108.5 feet = 25.9 per cent. 

 Length mid. body, 164.1 feet =39.1 per cent. 

 Length after body, 146.7 feet =35.0 per cent. 



In further reply to Professor Bragg's inquiry as to the character of the sections, the sec- 

 tions forward would probably be called of the "U" type, although they are by no means 

 full U's. The sections aft are V's and the form has easy buttocks, and also easy waterlines. 

 It should be noted from the proportion of form of the middle and after bodies given above 

 that the vessel had a long and easy nm for a vessel with a block coefficient as large as this one. 



Mr. James Kennedy, Superintendent of the Marine Department of the Gulf Refining 

 Company, which is operating the ship, has very kindly contributed copies of the deck and 

 engine-room logs for one of the normal voyages of this ship whose route lies between Port 

 Arthur and Bayonne, N. J. These are interesting in that they show normal operating con- 

 ditions. In this connection, however, it should be borne in mind that the vessel is operated so 

 as to take full advantage of the Gulf Stream on the northerly run, and this effect is notice- 

 able on the logged distances which are higher than would be obtained if operating on a 

 route with no current. (Plates 70, 71, 72 and 73.) 



The Chairman : — This is another of the papers which greatly enrich our Transac- 

 tions, and such facts represent the results of carefully conducted trials, something we can tie 

 to whenever our work may lead us into this particular field. 



I am sure you will desire me, on your behalf, to convey the thanks of the Society to 

 Professor Everett for his most interesting paper. 



The next paper to be presented is entitled "American Shipyard Apprenticeships, 

 Evening Schools and Scholarships," by Mr. Charles F. Bailey, Member of Council. 



Mr. Bailey presented the paper. 



