COFFIN. — EDGE CORRECTIONS IN CONDENSERS. 



427 



oc- 



t = 



< = + oo 



<^ AVlieii a = 1, or when we considei- the 



case of two scjuare corners facing one an- 

 other, as in the figure, the ecjuation (e) re- 

 duces to 



< = +l 



— V 

 in 



x-^- {!-] 



og'^)). 



00- 



^ = 



CO ■ 



t--l 



t — — <x> 



CO 



t = -ca 



CO 



When we let a become infinite the ex- 

 pression (e) becomes indeterminate, but by 

 determining its true value we find for the 

 case of a square corner facing an infinite 

 plane, the expression 



■t = + co 



9 = 



Air h 



2 A ,, 



^ + — (1 



low 2 



c5 



These two results check the general 



solution, as these special cases iiave 



.been worked out by J. J. Thomson.* 



As an approximate expression for these cases we may write ; 



g = - 



4 7rA V'^'^10 



and 



-477.(" + l) 



for 



for 



TI 



where — is used in place of h X .0978. 



* Rt't'ent TJer.enrflios in El. & Mag., Cliapt. on ronjugntc Functions. 



