142 



OCEAN ATMOSPHERIC -ELECTRIC RESULTS 



The present investigation indicates that all conduc- 

 tivity and potential-gradient measurements in the Pacific 

 on cruise VH of the Carnegie , regardless of whether the 

 conductivity results were derived from continuously re- 

 corded data or from daily eye-reading observations of 

 an hour or two, are in agreement in showing that the 

 ratio of positive to negative conductivity increases with 

 increasing value of potential-gradient. There is, there- 

 fore, general agreement on the indication that small 

 changes in field occurring in fair weather produce an 

 appreciable "electrode effect." This effect appears to 

 be most clearly demonstrated by the day to day eye- 

 readings of conductivity over the Pacific Ocean. For 

 those data both conductivities decrease with increase in 

 potential-gradient, but the negative conductivity is de- 

 creased more than the positive, thus giving an increase 

 in the ratio with increase in gradient. This may be seen 

 from table 2, where mean values of positive and negative 

 conductivity are tabulated with mean values of potential- 

 gradient. The mean values of the ratio of the conductiv- 

 ities are repeated here, taken from table 1. 



Taking, for example, the values of conductivity cor- 

 responding to 219 volts per meter, it is seen that the 

 positive conductivity is 25 per cent lower than it was for 



Table 2. Mean values of potential-gradient and corre- 

 sponding mean values of positive and negative conduc- 

 tivity and of the ratio of the two conductivities, 

 from data obtained in the Pacific Ocean 



Potential- 

 gradient 

 V/m 



Positive 

 conductivity 

 in 10-4 esu 



Negative 

 conductivity 

 in 10-4 esu 



Ratio 



x+A- 



No. of 

 obsns. 



102 volts per meter, but the negative is 33 per cent 

 lower. Other sets of data in the table give the same re- 

 sult; greater reduction of the negative conductivity than 

 of the positive, with increase in potential-gradient. 



