RESISTANCE OF BILGE KEELS. 21 



There has been a question raised as to how the bilge keels were put on. They were 

 made, as stated in the body of the paper, of good ^-inch oak, and were bolted on without 

 any fillet, which corresponds, as nearly as our scale would admit, with the ordinary practice. 



Of course, we cannot produce any answer from the experiments as to the effect of 

 ratio of beam and depth of the ship on the bilge keel for that ship, which were all made on 

 one particular boat. 



E. A. Stevens, Jr., Member: — Have you any information as to whether the resistance 

 of bilge keels increased in proportion to beam overlength of the ship? 



Professor Peabody : — I am sorry to say, Mr. Stevens, that our experiments did not 

 shed any light upon that question. 



I am exceedingly obliged to Mr. Taylor for the very interesting and important addition 

 that he has given to our experiments from the work which he has in his possession upon the 

 tests of the model of the Sotoyomo, and I will ask my colleague, Professor Everett, if he 

 can state whether the wave did or did not come near the propeller at the speed indicated 

 by the diagram. 



Professor H. A. Everett, Member: — I can only speak from memory. Professor Pea- 

 body, but at about five knots my impression is that the crest was immediately over the pro- 

 peller, and at our maximum speed we had not quite run away from the wave, and had not 

 quite reached the hollow. 



Professor Peabody: — Perhaps I may be pardoned if I state to the Society that the 

 rule governing our experiment was that when everything was in proper working order, 

 we excluded everybody from the boat except those who were in the actual charge of sailing 

 it, Mr. Everett and Mr. Constable, and I consequently did not have the information myself 

 which I am very glad to receive from Professor Everett. 



I shall not make any comments upon this addition of Mr. Taylor, which I should be 

 glad to study more at length when I have an opportunity, further than to express, as I have 

 already done, my gratitude for his addition. 



With regard to the test on battleships with and without keels, I am going to say that, 

 having spent, as we have, a number of seasons on making progressive speed trials under 

 ideal conditions, such as I believe have never been realized for tests of ships at sea, I am 

 not at all surprised that any tests made upon a ship with and without bilge keels failed to de- 

 termine anything about it. Having made some speed trials, and having had this experience, 

 I am the more surprised that progressive speed trials come out as close as they do rather 

 than that they are not better. I do not believe that this question can be solved in that fash- 

 ion. The suggestion which has been made by Mr. Taylor, explaining how that may have 

 happened to the particular battleship, is perfectly in order, namely, that the use of the helm 

 would be likely to make a resistance which might be as great as that of a keel, but I doubt 

 whether either of these actually was determined upon the speed trials which were made, even 

 though they should be made with all the skill and care which the Navy Department 

 is known to give to work of that sort. 



As to his suggestion, however, in regard to the use of a helm upon the Fulton, I will not 

 say that the helm was used very little on the Fulton, and with just about the same regu- 

 larity. 



