Prof. Franz Exner on Contact Electricity. 



287 



two mutually-related experiments, since for such the distance 

 between the condenser-plates must remain the same. 



In what follows, N denotes the zero-point for each consecu- 

 tive position of the telescope, a the observed deflection, 

 reckoned positive when towards decreasing numbers, negative 

 when towards increasing. The first vertical column contains 

 the numbers of the experiments. Each horizontal series 

 forms a complete experiment. A gives the reading with the 

 condenser and Daniel acting in opposition to one another, B 

 with them acting together ; G the value of x and D calculated 

 therefrom, where x represents the difference of potential of 

 the metals under examination, and D the electromotive force 

 of a Daniel, both expressed in scale-divisions. D gives the 

 reading of the check experiment, and E the value found 

 therefrom for x. F gives the mean of the values for x from 

 C and E ; and, lastly, G the value of x referred to a Daniell 

 as unit. 





I. 



Experiments with Zinc and Platinum. 









A. 



E. 



C. 



D. 



E. 



F. 



a. 



1. 



N=749 

 a =757 



N=749 

 a = 605 



#=68 

 D=76 



N=749 

 a =681 



#=68 



#=68 



#= 



= •90 



2. 



N = 852 

 a = 858*5 



N = 850 

 «=754 



#=44-7 

 D=51-3 



N=850 



a =806-5 



#=43-5 



#=44-1 



#= 



= •88 



3. 



N=804 

 a = 8ll 



N=806 

 a =696 



#=51-5 

 D = 58-5 



N=808 

 a =756 



#=52 



# = 51-7 



#= 



:-88 



4. 



N=857 

 a = 864 



N=857 

 a =766 



#=42 

 D=49 



N=857 

 a = 814 



# = 43 



#=42-5 



#= 



•86 



5. 



N=668 

 a =675 



N=668 

 a =556 



#=52 - 5 

 D=59'5 



N=668 

 a=615 



# = 53 



# = 52-7 



x= 



•88 



6. 



N=674 

 a =680 



N = 674 

 a = 552 



#=58 

 D = 64 



N=676 

 a=618 



#=58 



#=58 



x= 



•91 



7. 



N = 714-5 

 a =724-5 



N=715 

 a=655 



#=75 

 D==85 



N=714 



a=639-5 



#=74*5 



#=74-7 



x= 



•88 



8. 



N = 858 

 « = 865 



N=858 

 a =762 



07=44-5 

 D = 51-5 



N = 855 

 a— B10 



#=45 



#=44-7 



X — 



•87 



9. 



N = 848 

 «=855 



N=848 

 a =747 



# = 47 

 D = 54 



N= 847-5 

 a = 801 



# = 46-5 



#=46-7 



X — 



•86 



10. 



N = 720 

 a =730 



N = 720 

 «=560 



#=75 

 D=85 



N = 718 

 a = 644 



#=74 



#=74-5 



# = 



•88 



11. 



— 



N=808 

 a =694 



D=60 



]S T = 806 

 a = 752 



# = 54 



— 



# = 



•90 



12. 



— 



N = 808 

 a = 695 



D=60 



N = 808 

 a = 755 



#=53 



— 



# = 



•88 



13. 



N=855 

 a = 871-5 



N=855 #=457 

 a = 757 p= 52-3 



N = 853-5 

 a = 808 



#=45-5 



# = 45-6. 



X — 



•87 









Mean... #= 



•881 



