Fig. 9. Change in ratio X. + /X- with change in potential-gradient. Points are daily means of recorder values 

 of potential-gradient and corresponding ratios of daily means of recorder values of X+ and A -. Carnegie , 

 cruise Vn, October 5 to November 12, 1929 



Fig. 10. Change in ratio X+A- with change in potential-gradient, using eye-reading measurements of con- 

 ductivity obtained July 28, 1928 to October 9, 1928 in the Atlantic Ocean and November 5, 1928 to July 28, 

 1929, in the Pacific Ocean 



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