1909. | The Wave-making Resistance of Ships. 289 
We examine, now, some examples of experimental curves, comparing them 
with the formula (20) ; several of the curves and other data, in particular 
for II, ILI, and V, have been taken from the collection in Prof. Hovgaard’s 
paper already referred to, in which he essays to fit formule involving V‘ or 
V° with the experimental curves. 
I. &. #. Froude, 1881, Ship A. 
Displacement = 4090 tons ; length = 400 feet; cylindrical 
coefficient = 0°694. 
This is the case we have examined in the previous sections, so that we 
have only to change the numerical factors in (19) to cause R to be given in 
Ibs. per ton displacement. We find the result is formula (20) with 
a= 246; @=1626; y= 012. 
Il. W. Froude, 1877. 
Displacement = 3804 tons; length = 340 feet; cylindrical 
coefficient = 0-787. 
The last two data include the cylindrical middle body. The curve is 
given in fig. 5; it was constructed by Hovgaard from the data of Froude’s 
un 
R Tons 
US) 
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