74 



ELECTROTYPE PROCESSES. 



to 1 inch. These experiments were repeated several times, and a 

 mean of the whole taken : the results were, 



Deposited 



Electrodes 1 inch 



2 inches 



3 inches 



4 inches 



From this it will be seen that Wollaston's stands lowest in intensity, 

 which is more apparent as the distance of the electrodes is increased. 

 Smee's is one-third more than Wollaston's at 1 inch, and one half 

 more at 4 inches; while Grove's is three and a-half more than Wol- 

 laston's, and two and a-half more than Smee's at 1 inch, but four 

 and a-half more than Wollaston's, and three more than Smee's, 

 at 4 inches. If we take the mean of these results as a comparison of 

 batteries, their value will stand as under : 



One of Grove's equal to three of Smee's, 



and to three and three-fourths of Wollaston's. 



The following table gives the results of different batteries, arranged 

 in series, kept in action the same length of time, namely, one hour ; 

 the battery plates were very small, the electrodes twice the size of 

 the battery plates : 



This table gives results approaching to and in principle the same 

 as the others : it will be observed that one pair of Grove's is equal 

 to 9 pair of either Wollaston's or Smee's. It is also worthy of 

 remark, that Grove's increases slowly in quantity above 4 pair, the 

 intensity being sufficient at 4 pair to overcome the resistance offered 

 to the current of electricity. For ordinary electrotyping, intensity 

 arrangements are unnecessary, except where the article upon which 

 the deposit is being made is of such a character as will not allow 

 the positive electrode to be brought close to it, or when there are 

 deep cut objects, or any circumstance that increases distance and 

 necessitates power to overcome resistance. 



