EXPERIMENTS ON SIMPLIFIED SHIP FORMS. 161 



The results of the tests are shown in Fig. 13, Plate 95, and in general are of 

 the same character as in the previous series. 



The effect of retaining the corner volume at the bilge is to increase the resistance 

 about 3 to 4 per cent, or approximately the same as that due to the added surface. 



Compared with the shipshape form, there is practically no difference in resist- 

 ance between this and the simplified form with the corner cut off. 



Although time did not permit of carrying out a complete set of rolling experi- 

 ments, some of the models were tried and it was found that the effect of the sharp 

 corner upon the reduction of rolls was most marked, and that even with the corner 

 removed these models came to rest quicker than the shipshape form. 



The general conclusions that may be drawn are as follows : — 



1. Vessels of the straight frame type can be designed which will have about the 

 same resistance as a shipshape form. 



2. If the diagonal line of the corner be given the wrong slope, this will increase 

 the resistance due to the lack of conformity with the proper stream line flow. 



3. The effect of maintaining the square corner is to increase the bare hull re- 

 sistance, but as vessels of this form would not need bilge keels the net result from a 

 horse-power standpoint would be about the same as for a shipshape form. 



4. Probably the best results from a resistance standpoint would be obtained by 

 using diagonal line which is of a curved form in the body plan. 



DISCUSSION. 



The President : — We will now have paper No. 10, entitled, "Variation of Shaft Horse- 

 Power, Propeller Revolutions and Propulsive Coefficient with Longitudinal Position of the 

 Parallel Middle Body in a Single Screw Cargo Ship," by Commander William McEntee, 

 Naval Constructor, U. S. Navy, Member. 



Let me say, gentlemen, that it is not our fault in any way that the copies of the papers 

 were not received in time for your examination previous to the reading. Copies were dis- 

 tributed by mail to our members, and the copies for distribution here were sent by express 

 from Washington several days ago. One of two things happened, either that they were not 

 properly shipped — which I do not believe to be the case — or the Director-General of Rail- 

 roads and Express Companies is not "on to his job." 



Commander McEntee then presented his paper. 



