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MR THOMAS ANDREWS ON THE RELATIVE 



Table F. 



Galvanometer Experiments with Bright Steel, Wrought Iron, Cast Metal Bars, $e. 



Description. 



Percentage 

 of Com- 

 bined 

 Carbon. 



SOLUTION IN WHICH THE BARS WERE IMMERSED. 



One-Fifth Normal Standard Sulphuric Acid. 



Zinc Rod forming one 



Element with cacli of 



following. 



Wrought Iron Bar 

 forming one Element 

 with each of following. 



Iron Scale (Magnetic 



Oxide) forming one 



Element with each of 



following. 



Deflection 

 of Galvano- 

 meter in 

 Degrees. 



1 



Electro- 

 chemical 

 Position of 

 the Metals. 



Deflection 

 of Galvano- 

 meter in 

 Degrees. 



Electro- 

 Chemical 

 Position of 

 the Metals. 



Deflection 

 of Galvano- 

 meter in 

 Degrees. 



Electro- 

 Chemical 

 Position of 

 the Metals. 



Sjft Siemens-Martin steel, 





8-90 



N 



0-62 



P 



14-15 



P 



Wrought iron, 



Trace 



10-10 



N 







1490 



P 



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



0-570 



8-89 



N 



0-25 



N 



14-87 



P 



Bessemer steel, ..... 



0-55 



9 03 



N 



0-55 



N 



13-80 



P 



Puddled steel, .... 



0-44 



8-08 



N 



0-60 



N 



13-90 



P 



Puddled steel (chilled), . 



049 



9-97 



N 



0-90 



N 



13-77 



P 



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



1-600 



8-84 



N 



0-57 



N 



14-95 



P 



Cast metal (graphitic carbon, 2'40 ) 

 per cent.), ) 



1-00 



12-50 



N 



0-95 



N 



15-07 



P 



Tungsten steel, ..... 



1-75 



9 40 



N 



016 



N 



14-27 



P 



Bemarks. 

 Each result is the average of ten observations made in the same manner f >r exact compuison. 



A reference to the analyses of the steel plates s-hows that, as regards 

 manufacture, they were selected from three of the most important classes 

 of steel, viz., Bessemer, Siemens-Martin, and cast steel, and a sample of the 

 softest and hardest temper was taken from each kind. 



