172 Mr. C. Binks on Electricity^ 



118. But in the instances that immediately follow, the ex- 

 periments will be restricted to that condition of the arrange- 

 ment in which the zinc plate is the smaller of the two. 



119. The plates used in the preceding experiments were 

 each one inch square (93); but one side of the zinc being co- 

 vered with wax, was not brought into action, whilst both sides 

 of the copper plate were exposed to the action of the acid 

 throughout: the total area of the zinc surface was therefore 

 equal to one square inch, and that of the copper to two square 

 inches. 



120. The experiments to determine the further effects of 

 distance are now to be varied by the use of larger copper 

 plates, whilst the magnitude of the zinc plate remains precisely 

 the same as before. 



121. The set of copper plates prepared for these and the 

 subsequent experiments amounts in number to 13, beginning 

 from the size of 2 square inches of total surface, as in the one 

 above, and progressively increasing by the following rate : — 



122. Total superficial area in square inches of each copper 

 plate. 



2. 4. 8. 12. 18. 24. 32. 40. 50. 60. 72. 98. 128. 



123. Each plate was attached to a wire 5 feet in length, in 

 the same manner as before. The various precautions used in 

 preparing this set of plates, and in adapting them to their 

 present use, have already been fully explained (62). 



124. Now the immediate object of the inquiry is to ascer- 

 tain what influence is exercised by distance upon any arrange- 

 ment which may be composed of a zinc plate having a total 

 superficial area of 1 square inch, and of a copper plate whose 

 area is any of those just stated (122). The relative distances 

 contemplated range between \ of an inch and 48 inches ; and 

 to complete the investigation, the acid mixture should be va- 

 ried in strength in the four different degrees used in the for- 

 mer experiments. 



125. A little consideration will show how innumerable and 

 varied the experiments would need to be, in order to com- 

 plete an investigation which should undertake to determine 

 the effects of distance under all the varied changes of the con- 

 ditions of such arrangements of which they are capable. 



126. But it will perhaps be unnecessary to pursue the in- 

 vestigation to so great a length. Such results as it may be 

 desirable to seek for will perhaps be obtained by a very few 

 observations comparatively ; and as most likely to contribute 

 to this abridgement, the order of the experiments as they now 

 follow was determined upon. 



127. The amount of action yielded by any voltaic arrange- 



