SOME MODEL BASIN INVESTIGATIONS OF THE INFLUENCE 
OF FORM OF SHIPS UPON THEIR RESISTANCE. 
By Nava Constructor D. W. Tayvtor, U. S. N., Vick-PRESIDENT. 
[Read at the eighteenth general meeting of the Society of Naval Architects and Marine Engineers, held in 
New York, November 16 and 17, 1911.] 
It is impracticable to fully investigate the influences of the form of 
ships upon their resistance, even when we restrict the expression “form” 
to the shape of a ship apart from dimensions and proportions. 
If there were a definite number of possible forms we might cover them 
all experimentally in time, but the field is infinite in every direction. Thus 
for a vessel of given dimensions and displacement we might have an infinite 
number of shapes of midship section, for the fore-body, an infinite number 
of shapes of the water-line and of the curves of sectional area, and similarly 
for the after-body. 
The case, however, is not quite hopeless as regards results of practical 
value. If, for instance, the shape of the midship section had no influence 
upon resistance we need not explore that field at all. 
In a paper three years ago before the Society upon the influence of 
the shape of the midship section upon resistance I showed that within the 
range of a limited number of experiments the influence of the shape of the 
midship section upon resistance, while appreciable, was not great, and for the 
variations practicable in a given case would usually be almost negligible. 
The present paper gives the results of some experimental investigations 
of the effect of shape toward the extremities. The field is a very broad 
one and the experiments are far from completion. The results now given, 
however, are complete in themselves and it is believed throw a light on the 
portion of the field they cover. 
Table I gives coefficients, etc., for two series of models, namely, Series 
Nos. 29 and 32. ‘The displacement in fresh water was in every case 2,250 
pounds and the length of each model 20 feet. “The midship section coeffi- 
cient was in each case 0.96 and the ratio of beam to draught 2.5. The longi- 
tudinal coefficient} of Series No. 29 was 0.60 and Series No. 32,0.64. Hence, 
the beam and draught in Series No. 32 were slightly less than in Series No. 29. 
It will be observed that each series consists of 16 models. This resulted 
from the fact that in each case four different curves of sectional area were 
