1 74 Mr. C. Binks on Electricitt/, 



would be followed by a corresponding increase in the action 

 of the whole arrangement; and it might be presumed also, 

 that inasmuch as the amount of action given by the standard 

 plate is reduced from 3 to 1 by the removal from ^ of an inch 

 to 24 inches, but to a less extent in the intermediate positions, 

 it would require a larger plate at 24 inches to restore the stand- 

 ard amount than at any of the intermediate positions, or in 

 other words, that a copper plate progressively smaller would 

 be required to restore that amount as we progressively ad- 

 vance to positions nearer to the zinc or standard position. 



134. It will be of some advantage at this stage, before pro- 

 ceeding on to the more specific details, to give a general out- 

 line of the kind of results which have been obtained by the 

 experiments entered upon to determine the points just sug- 

 gested ; only premising that the numbers and positions now 

 used must be considered as illustrative merely, and not as 

 actual representations of any one particular instance of the 

 general phaenomena and relations which have been thus de- 

 tected; the whole of which, it will be found subsequently, are 

 influenced by a variety of circumstances which could scarcely 

 have been anticipated, and which it becomes the particular 

 business of the inquiry to detect and estimate as it proceeds. 



This general illustration is given in the hope that it may 

 serve to simplify and more clearly define the nature of the 

 somewhat complicated examinations upon which I am now 

 entering, the precise numerical results of which are immedi- 

 ately to follow. 



1 35. Let it be supposed that the trials are made in a mass 

 of liquid contained in an oblong-shaped trough, similar to 

 that used in the experiments of the last section. 



136. Let the amount of action given at the distance of ^ of 

 an inch by small standard plates be supposed equal to 3, 

 and that obtained at 24 inches off equal to 1 ; then, whilst at 

 the latter position, let the small copper plate be removed, and 

 others progressively larger be substituted for it in succession ; 

 and it will be found that by no increase whatever to the size 

 of the copper plate, can the same amount of action be obtained 

 at 24 inches, that was found by the small plate at the first or 

 standard position. A certain increase in amount will be ob- 

 tained, perhaps equal to 2, but in no case to 3, the amount 

 required. 



But let the same trials be now repeated at other positions 

 nearer to the fixed zinc plate, say at the several positions 

 reached by successive steps of 2 inches each, when the follow- 

 ing unexpected results will be presented: — It will be found 

 that neither can the required amount, 3, be obtained at any of 



