EXPERIMENTS ON THE FULTON AND THE FROUDE. 15 



than the smallest ratio used in the experiments described by Professor Peabody. 

 The power was 3,600 indicated horse-power. The Nadeshny was tried in the 

 autumn of 1897, in the Finnish Gulf, where she maintained a steady speed of 3 to 4 

 knots through floe ice of a uniform thickness of 29 inches. She was subjected to 

 several other successful tests which showed her excellent qualities as an ice-breaker, 

 and bore out the advantages of a low-pitch propeller of moderate blade area. 



Mr. CivINTon H. Crane, Member: — I think that all of us in this Society, if we 

 believe in this Society's worth, must appreciate a scientific investigation of any 

 problem. I think all of us who have to do with the designing of tug-boats, the 

 building of tug-boats, and the handling of tug-boats, realize that there is less 

 scientific information about a tug-boat than about any other type of boat that is 

 built in this country. 



Some years ago we were called on to design a tug-boat for the Brooklyn Eastern 

 Terminal. They had never used anything at all but wooden tug-boats. There 

 was not a man in the place who would have anything to do with a steel tug-boat, 

 because a wooden tug-boat " towed better." When asked, "Why does a wooden 

 tug-boat tow better?" the reply was — "I don't know, but I have been on the 

 Sempt, and know that she is better than any tow-boat in the harbor. " I made a 

 great many trips on the wooden tow-boats and looked into the steel tow-boats, and 

 we finally built a steel tow-boat. When that tow-boat was finished, she was not 

 doing work equal to any of the wooden boats; none of the men in the yard thought 

 she was doing half as well — that was their opinion. We said, "All right; let us run 

 a comparative test and let us see what the boats will do. ' ' We very carefully 

 measured the water and weighed the coal, and timed the boats handling car floats 

 in and out of the dock, and the time taken to convey the float from dock to dock, 

 and we ran that thing for a period of over two months, and then we found that 

 the steel tow-boat was doing 10 per cent more work than any of the other boats; 

 but, all the same, she was no good, and even after the test was finished, the old 

 shell backs were not convinced. My experience with tow-boat propellers is that 

 the general idea is unless you put on a square tip, high pitch-ratio propeller, it 

 is no good. I have personally been convinced for a long time that a low pitch 

 propeller would tow better. It is absurd to use a slip of 60 or 70 per cent when 

 you do not have to, and yet the times when we have put on low pitch-ratio pro- 

 pellers — and we tried them several times — they have never been a success. It is 

 perfectly fair to say, as a matter of fact, that a low pitch-ratio will not handle the 

 boat as well as a high pitch-ratio. It will not get the power to her as well, nor stop 

 the boat as well, nor turn her as well — just why that is I have not been able to 

 determine to my own satisfaction, and I rather hoped that Mr. Peabody, in his experi- 

 ments, had made some handling experiments which would help us in that analysis. 



I believe that the meal which Professor Peabody has prepared for us is v/orthy 

 of a very careful digestion. It is a very full meal, and I think there are very few 

 of us who can say how much we can use, and how much we cannot use, until we 



