AMERICAN LEGION CLASS. 201 
If you consider the plate giving the details of the trial of the President Pierce from 
the economy standpoint, you will find at the left hand of the plate, at the 15.4 knot speed, 
the average revolutions were 101.7, and the two powers added together 7,110. 
Take the next line below, speed not given; average revolutions 102.9, and the power 
9,565, an increase of 2,400 in the power for 1.2 revolutions. That was probably due, I 
should say, to the question of depth of water. It is very likely that the high power was 
run in unusually shallow water, but that is the kind of thing we always run against when we 
attempt to go back to the original data in test trials. 
Another factor in connection with trials is the question of a steering. We were told 
yesterday that bad steering would add to the resistance 16 per cent. I do not know whether 
the steersman in these trials is guaranteed but maybe that will account for the whole 
difference. 
In regard to the depth of water, I think there is no question it must have had some 
effect, but if you take Rota’s results, which are perhaps as good as any, on that, you will 
find, according to him, there will be practically no increase in resistance up to 13 or 14 knots, 
and that the increase would be comparatively low, probably for a knot or two beyond that; 
and as we find there is quite a discrepancy between 13 and 14 knots, there seems to be little 
question that the depth of water could not account for the whole difference, although it was 
one factor. 
You will find, if you plot the power upon the revolutions instead of speed and plot 
the economy runs as well as the speed trials, while the power for various revolutions seems 
somewhat erratic, particularly the one speed I have referred to—generally speaking, the 
economy run falls fairly close to the standardization run, though I understand that the econ- 
omy runs were made in much shallower water. If the runs on this course and in much 
shallower water agree, it is rather a reflection upon the accuracy of one or the other. 
Let us consider the problem in detail for a minute. Curve B in Plate 58, again, is not 
deduced from experiments with the President McKinley model. It was deduced from ex- 
periments with the model of the American Legion, with a different propeller. Although, as 
pointed out by Mr. Warriner, the difference is probably due to lack of smoothness of the pro- 
peller of the American Legion, and that might make up partially for the smaller size and 
smaller pitch ratio of the propeller of the President McKinley, that would not apply to 
the model experiments. In the model experiments the propeller of the American Legion 
was undoubtedly just as smooth and carefully finished as it would have been if it had been 
the model of the President Pierce, so that that is another factor, all tending in the same 
direction. 
Now we come to the question of the condition of the bottom. I would like to ask Mr. 
Warriner how long the vessel has been out of the dry dock? 
Mr. WarRINER :—Something like two weeks. 
ADMIRAL TAYLOR:—The President Pierce was in practically fresh water. How long 
had it been in the fresh water? 
Mr. WaRRINER :—Five days. 
ApMIRAL TAyLor:—We have had some experiments recently in the matter of the foul- 
ing of ship’s bottoms which brought home to us more than ever the fact that this fouling is 
