214 



Mil THOMAS ANDREWS ON THE RELATIVE 



Table H. 



Galvanometer Experiment* with Copper, Steel, Wrought Iron, and Cast-Metal Plates, #c 



Description 



Percentage of 



Combined 

 Carbon. 



WATER IN WHICH THE PLATES WEUE IMMERSED. 



Ska-Watkr. 



Copper Plate (Bright), forming one Element with each of the 

 following Bright Steel, &c, Plates. 



Deflection of Galvanometer in Degrees. 



Elect ro- 

 Cliemical Posi- 

 tion of the 

 Metals. 



Average. 



Highest. 



Lowest. 



Soft Siemens-Martin steel, 



0170 



6-17 



9-50 



4-50 



P 



n Soft steel (Firth's), .... 



0-460 



6-15 



9-00 



4-25 



P 



Wrought iron, ..... 



Trace 



8-62 9-75 



4-50 



P 



Soft Bessemer, ..... 



0-150 



6-74 



9-50 



5-25 



P 



Hard Bessemer, .... 



0-510 



7-33 



975 



5-40 



P 



Hard Siemens-Martin steel, 



0-720 



7'25 



9-50 



5 - 75 



P 



Hard steel (Firth's), .... 



1 -407 



7-05 



8-00 



5-50 



P 



Cast metal,* 



2-01O 



7-26 



10-50 



5-75 



P 



* Graphitic carbon, 1 -50 per cent. 



Remarks. 



Each of the above results is the average of nineteen observations, each taken at e<jual d stances of time, 

 each experiment extending over three hours. 



