S#4 Dr. W. H. Eccles on Coherers. 



Here a is essentially positive. The quantity b has the 

 same si on as de/dc, as may be seen by differentiating (3) and 

 comparing (7) and (8). Since my experiments have been 

 for the most part confined to self-restoring coherers, b has 

 been in practice always positive. Tims (8) yields 



8 Pl =Ae- m ^-\-Be- m ^, .... (9) 



where a/- , /., 4/A 



It appears later that a 2 is always much greater than 46, so 

 that, approximately, 



in^ 2 =b/a or a — bja* 



The only datum available at the moment for determining 

 the arbitrary constants A and B in (9) is that the initial 

 value of Sp 2 is (Spi). Therefore 



(10) 



(Sp,) = A+B. . . 





Using (9) in (4), 





L * +(f+Pl)8Cl= " CllArMl< + B '' 



-m 2 t\ . 



J 5 



whence 





_ r -±h t _ r _±P] t 



L L r + p, r + P, J 



-jQ— — m x — ^ m 2 



. . . (11) 

 which vanishes at t = 0. 



Let the w T ork done in the telephone by the fluctuation of 

 the current through it be m? 1? and let the effective resistance 

 of the telephone be P. Thus the rate at which the telephone 

 current is working at any moment is P^ 2 , and } therefore, 



c 1 2 d*=2Pc 1 i hc x dt. 



*o Jo 



Equation (11) now gives 



2P 2 TA B " 



Wi— — ■ <?i i — + — 



r + Pi U^i nh. 



r + Pi m 2 L ™ Wi 



by using the condition (10). 



