BiRKS AND Webb. — Resistance of Earth Connections. 



471 



ingly large range of resistances is then explicable by electrolytes of variable 

 specific conductivity, determined by the solutes or the degrees of concen- 

 tration. That such is a feasible explanation is evident from the following 

 specific conductivities of electrolytes (" Physical and Chemical Constants," 

 by Kaye and Laby), which admit of combinations to provide almost infinite 

 range of values (diagram No. 2). 



^ 16 24 32 -^O 48 



Percentage of mo/jrure contained 



Fig. 1. 



S6 



€4- 



72 



eo 



Specific efectric conducrivity o/ims ~' cm. ~' 



Fig. 



In the course of this investigation a few comparatively very low-resist- 

 ance " earths " were obtained, ranging from 4 to 40 ohms- — e.g., at Wind- 

 whistle Point single pipes gave 20 ohms ; at Acheron Eiver single pipes 

 gave 35 ohms ; and see values in Table VIII : all by A.C. bridge method 



