212 



Profs. W. E. Ayrton and John Perry. [Mar. 21, 



Interval of 10 minutes. 



Zero. 



Heading. 



Deflection. 



953 -1 



960 -0 



6-9 



953 -2 



945 -0 



8-2 



953 -1 



961 -2 



81 



953 -3 



945 -2 



8-1 



953 7 



961 -0 



7 3 



953 '9 



945 -2 



8 7 



Mean of first six 8 '3 or 191 volt. 



Mean of last six 7 '9 or '182 volt. 



Table IX.— 14th April, 1876. Plates 10 mm. apart. 



Zinc and very dilute zinc sulphate (17° C.) in contact. Zinc negative 



to liquid. 



Zero. Reading. Deflection. 



1066 -0 1073 -1 7 -1 



1065 -3 1057 -3 8 '3 



1065 -1 1072 3 7 -2 



10651 1057-0 8 1 



Mean 7 7 or 177 volt. 



Copper and very dilute zinc sulphate (17° C.) in contact. Copper is 

 positive to liquid. 



Zero. Reading. Deflection. 



1060 -0 1060 -9 -9 



1060 -0 1058 -8 1 -2 



Mean 1 '35 or "024 volt. 



Slightly impure copper sulphate (at 22 0, 3 C.) and very dilute zinc 

 sulphate (17° C.) in contact. Copper sulphate is positive. 



Zero. Reading. Deflection. 



1058 '0 1055 -8 2 -2 



1058 -4 1061 7 3 3 



Mean 2 75 or "066 volt. 



Copper and slightly impure copper .sulphate (2 7° '3 C.) in contact. 



No perceptible deflection. 



Dipped copper in the above copper sulphate and zinc in the zinc 

 sulphate and connected directly with electrometer. 

 Deflection 246 or 1 '010 volts. 



We were subsequently rather sorry that so few observations were 



