OF CKI;TAIN roi;\i> 



MIAFTIM:. 



kc\ \\ii\s, cut into thtMii along the major axis, as far as the foci. The stress at tin- 

 f<>ci, however, is then theoretically infinite. 



It is interesting to see ho\v. .is \\c m; ( k.- the I KM id round the loci shaqier, the 

 value* nt', for which the two i'uil-puiiits break up into four. l>ecoine larger and larger, 



Fig. 6. 



Fig. *. 



until, when the angle between the asymptotes of the hyperbolas is less than 73^, the 

 greatest stress always occurs at the iieck of the section. 



The limiting case of such sections, when the angle between the asymptotes is very 

 small and the eccentricity of the ellipse nearly unity, the distance between the foci 

 being very great, gives us the rectangle. 



I then pass on to the section bounded by one ellipse and one coufocal hyperbola. 

 In tin- limiting case when the foci coincide, we obtain the sector of a circle. 



\M|. . \( HI. A. 'J 



