194, 195] DIELECTRICS AND MAGNETIZABLE BODIES. 



373 



pointing in its own direction or the opposite are shown in Figs. 74 

 and 75 respectively. 



FIG. 75. 



The field of the sphere in a uniform field is shown for p/fa = 3 

 and p/fa = oo respectively in Figs. 76 and 77. These figures were 

 originally given in Lord Kelvin's Reprint of Papers on Electro- 

 statics and Magnetism, (p. 492), where the equations of the curves 

 are discussed. The figures have been re-drawn for this book, the 

 lines being drawn for equal increments of the flux-function M*, 

 or p, 103 (10). 



FIG. 76. 



195. Infinite Elliptic Cylinder. If one of the axes of the 

 ellipsoid is infinite, we have the case of an infinite elliptic cylinder. 

 If c = oo , JV" is zero, and L, M, reduce to trigonometric forms. The 

 force parallel to the -axis is the same as that of the undisturbed 



