1909. ] The Wave-making Resistance of Ships. 291 
IV. D. W. Taylor, Model No, 892.* 
Displacement = 500 Ibs.; length on water line = 20:512 feet; longitudinal 
coeff. = 0°68; midship section coeff. = 0°70. 
In this case the experimental curve is given as lbs. per ton displacement 
(It’) on a base of speed-length ratio (c). In the same manner as before, fig. 7 
shows the comparison with the formula (20) when we take 
a=—2; B=825; y=014. 
Since the constant « is small compared with 8, one is not able to lay 
much stress on the meaning of the first term. For as the velocity functions 
are of a suitable type, the constants possess considerable elasticity as regards 
fitting an experimental curve. For instance, if we omit values of ¢ below 
about 0°9, it is possible to represent the previous curves fairly well by a 
formula 
R = B {1—y cos (10-2/c?)} e230, 
In the previous examples we took the value 1:3 for c’. In Case IV above 
we find now the values 
S=S=803 qSOide =i 
For a similar curve taken from the same paper, viz., Model No. 891, dis- 
placement 1000 lbs., we find a good correspondence, except for slightly higher 
values near c = 1:1, with the values 
B=174; y=014; c=14, 
*D.W. Taylor, Trans. S.N.A.M.E., vol. 16, p. 13 (1908). 
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