116 EXPERIMENTS ON THE FROUDE. 
DISCUSSION. 
VICE-PRESIDENT McFarianp:—Gentlemen, Professor Peabody’s paper on 
‘Experiments on the Froude” is now open for discussion. 
Pror. H. C. SapLeR, Member of Council:—Mr. Chairman and Gentlemen, I 
regret I have not been able to examine this paper in the detail I should like, and 
which I intend to do in the future, but I think that Professor Peabody is to be 
congratulated on the good work he is doing in this connection. I have always 
felt that the determination of wake in the ordinary model tank was open to a 
certain amount of doubt. The quantities measured are comparatively small, the 
propellers used are also small, and I think that estimates of wake may not, under 
these conditions, be very accurate. 
Here we have a much larger scale experiment than is possible with the ordinary 
tank, and I think in that way, perhaps, Professor Peabody may be able to give us in 
the future some more definite values of wake, as it is ordinarily understood, than 
that which we have at present. 
The results shown in Table 9 are very suggestive in that connection, as well as 
the diagram in Fig. 11, Plate 45, showing the variation of the wake intermsof distance 
of. the propeller from the ship. ‘ 
The influence of the form of the vessel upon wake is another point which I hope 
Professor Peabody may be able to take up in the near future, if it is possible to re- 
model the stern of the vessel without much trouble; for example make changes in the 
stern water lines and find the effect of these upon wake, and I think it will be of 
great advantage as throwing further light upon the stream line flow at the stern of 
the ship. 
Mr. CLinTon H. Crane, Member:—Mr. Peabody’s experiments with the Froude 
are extremely interesting. I do not think that I have the right to claim to being the 
father of such a method, but back in 1905, in connection with a paper which I read, 
I suggested the great value of experiments performed on small launches with refer- 
ence to the effect on larger sized vessels. 
On the other side, when I was on the East Coast, I saw a model which had been 
made of the Mauretania, and run back and forth in one of the docks, in an endeavor 
to obtain a good deal of the sort of data which Mr. Peabody has given to us, and 
which I believe the experimenters on the Mauretania model kept to themselves. 
That same year I saw a large model, about 50 feet long, at Denny’s and they 
said, in spite of their model basin, they felt for certain propeller problems it was 
necessary: to carry on tests similar to those Professor Peabody carried on. 
a 
