Dr. Yv T . H. Eccles on Coherers. $S~) 



Now, as stated before, (8pi) = — kpooi'Wi, where W T is 

 that portion of the energy of a single train of oscillations 

 usefully converted to heat in the detector. Therefore (12) 

 becomes 



^I^.^/w.-Af^Al . (i 3 ) 



to I 



The experiments have shown that the term involving the 

 arbitrary constant A is always positive. Hence, if A be 

 positive, m 2 must be greater than m, ; moreover, (10) shows 

 that B must be negative when, as was always the case, (Spi) 

 is negative. These considerations applied to equation (9) 

 imply that Bp l runs through a series of diminishing negative 

 values, passes through the value zero, and becomes positive. 

 This is not possible. On the other hand, if A be negative, 

 m 2 must be less than w» l5 and B may be either positive or 

 negative. If B be positive, (10) shows it must be numerically 

 less than A, and then the condition m 2 < m l implies that Bp l 

 in equation (9) changes sign once during its history. Re- 

 jecting this case we are left with A and B both negative and 

 m 2 <m l . The quantity m 2 must, therefore, be given the 

 value b/a and m x must equal a — h/a. Put A= — / 2 , and (13) 

 becomes 



1 r + Pl b \ 1 kp *\ cr-b) / 



This equation regarded as an equation between the energy 

 W x spent in the detector and the energy to, delivered by the 

 detector to the telephone, is precisely of the form required 

 by the experimental curves of figs. 4 and 5. Those curves 

 may be regarded, in fact, as determining the constant of 

 integration f 2 . The methods of measurement are not yet 

 sufficiently refined, however, to make it worth while to 

 examine this intercept term in detail. The coefficient 

 of Wi, on the other hand, may be profitably enquired 

 into. 



In this coefficient P, k, p , a, and r (which includes P, of 

 course) are to be taken as constants, while p ls a, b have values 

 dependent on the square of c^ the direct steady current 

 passing round the detector circuit. By aid of equations (6), 

 (7), and (8) the part of the coefficient which varies with c x 

 may be expressed in terms of the quantity n defined by (6). 

 This quantity n, it should be noticed, is itself a function of 

 the square of c l5 and therefore the following discussion applies 

 equally to positive and negative steady currents through the 



