47 



Figure 26 - S{y) for Some Lines ^ = O.6O 



Figure 27 - S(y) for Some Lines 4> = 0.64 



Extended investigations were made on fuller forms following the same 

 lines. However, less success was reached with respect to the applicability of 

 results ;^^ Figure 22. 



We were not able to develop forms with prismatics of O.72, which 

 have actually a low resistance at a Froude number above about 0.22. Up to 

 this limit an equation (6,8,10; 0.72; 2) yields theoretically excellent re- 

 sistance qualities; unfortunately, experiments have not corroborated the cal- 

 culations. 



The degree of the polynomials used (sectional-area curves) which is 

 indicative of the amount of parallel middle body, is sometimes more decisive 

 than the choice of t and, within narrower limits, even <l> . Thus, it can happen 

 that for low Froude numbers the resistance may not be very sensitive to 

 changes in ct> provided an upper limit is not exceeded. 



