THE LEAKAGE FACTOR. 



with the conditions underlying the leakage in polyphase motors. I 

 am far from claiming for this treatment completeness or conclusive- 

 ness ; on the contrary, I deem it a necessity to revise it by the light of 

 forthcoming experience. I am tolerably confident that the main pro- 

 positions will be proved true, while minor points may need some 

 qualification. 



63. Considering the immense complexity of the phenomena in poly 

 phase motors, the greater or less arbitrariness which hangs about most 

 of our assumptions which have to be made in order to be able to 

 calculate at all, I cannot forbear from wondering that so approximate 

 a solution can be attained at all. It may be that there are errors in- 

 herent in our fundamental assumptions which all so counteract one 

 another as to cause the result of calculation to deviate but little from 

 experiment and observation. This view will commend itself to those 

 who are familiar with any branch of physiology, for instance, 

 physiological optics ; here we have the testimony of Helmholtz that 

 the eye, having "every possible defect that can be found in an optical 

 instrument," yet gives us a fairly accurate image of the outer world 

 because these various defects balance one another almost completely. 



64. The above remarks will be distasteful to those who have accus- 

 tomed themselves to look upon only one side of a question, and try to 

 shut their eyes to the inevitable uncertainties that beset us in all intel- 

 lectual problems. I was once taken to task by a critic for having ad- 

 duced experimental evidence qualifying my theory, and narrowing 

 the limits of its application, and I was told that these experiments in- 

 validated my argument, while my intention to lay stress upon the in- 

 completeness and the shortcomings of the theory was obviously not 

 even thought of by my critic. Lawyers may have to hide the weak 

 sides and spots of their arguments, but men of science are bound to 

 point them out and expose them. 



The formulae and rules of the preceding articles will now be 

 turned to account in the following part by applying them to the 

 calculation of a motor. 



41 



