EXPERIMENTS ON THE FULTON AND THE FROUDE. 17 



I cannot believe that the wide stern post of a wooden tow-boat is a determining 

 reason for the typical wide-tipped tow-boat propeller, for our medium width, well- 

 rounded blades did well on the Froude, which has a wide stern post. 



We did not make experiments on stopping and starting and handling in 

 general, as we had not time last summer. Several speakers claim that a coarse 

 pitch wheel will handle a boat better than a fine pitch wheel, doubtless with good 

 reason ; if we have opportunity we will try this also and ask that weight shall be 

 given to our experience. 



I venture to suggest that stored power turned suddenly on a slow engine may 

 have less alarming effects than would be found with a quick running engine. And 

 further, quick-running engines must in general be built and run with more care ; 

 and yet automobile engines and power-boat engines manage to take care of them- 

 selves in the hands of unskilled people. 



While we claim we have obtained important results we have no desire to 

 recommend specific conditions, but, rather, we wish to enable the practical designer 

 to choose his conditions with wider information. In particular our range of pitch- 

 ratios was designedly taken wider than need be used in good practice, and I have 

 no desire to urge low ratios and quick engines for a service where so much depends 

 on employing inexperienced men. 



It is gratifying to learn that the experience of my colleague, Captain Hovgaard, 

 corroborates our conclusions. 



The statements concerning the service of tow-boats given by Mr. Crane call 

 to mind anecdotes by tow-boat men. When solicited by a tow-boat captain they 

 change the propeller and he always reports that the wheel he favors does very much 

 better. On one occasion a certain wheel was taken off to be changed, and by mis- 

 take was put back on again; nevertheless the captain reported the boat to be 

 doing very much better. I believe that any tow-boat captain who favored a wooden 

 boat could make it out ten per cent better than a steel boat, even though Mr. 

 Crane proved the advantage to lie the other way. 



One more point only I wish to emphasize : our indirect drive allowed me to 

 change from a large pitch to a small pitch and yet to drive with full power for each 

 wheel ; this you cannot do with a steam-engine or an internal-combustion engine 

 which must run at its own proper speed to develop its power. If you choose too 

 large a pitch-ratio you slow the engine below its power, but if you take too small a 

 ratio the engine runs away before it can develop its power. 



The President: — The thanks of the Society are due to Professor Peabody for 

 his very able and interesting paper. 



We will now have the paper entitled, "The Design and New Construction 

 Division of the Bureau of Construction and Repair of the Navy Department," 

 by Naval Constructor R. H. Robinson, U. S. N., a Member of Council. 



Mr. Robinson presented the paper. 



