ELECTRO-CHEMICAL POSITIONS OF WROUGHT IRON", ETC. 



2J7 



• Experiments on the Galvanic Action set up by a series oj B irs of Wrought 

 Iron and various Steels immersed in Sea- Water. 



The sample bars were portions cut from the same rods whose composition 

 and general properties have been previously described. 



The deflections of the needle of the galvanometer are shown in the accom- 

 panying tables K and L. 



Table K. 



Deflection of the Galvanometer Needle, produced when Bars 0/ Wrought Iron and Hard Cast 

 Steel (all of the same size and polished bright) were immersed in Sea- Water forming the 

 elements of Galvanic Action. Average of eight Experiments in each case.. 





Deflection of Needle. 



3 Bars of 



wrought iron connected 



with 3 Bars of hard cast steel, 



1'28 degrees 



4 „ 



» 





4 „ 



1-38 „ 



5 ,, 



>> 





5 „ 



1-52 „ 



6 „ 



it 





6 „ 



1-75 „ 



7 „ 



>> 





7 „ 



212 



8 „ 



» 





8 „ 



2-25 



The wrought iron was the electro-positive metal. 



Table L. 



Deflections of the Galvanometer Needle produced when Polished Bars of the Wrought Iron anl 

 the Soft Steel, the same size, xoere immersed in Sea- Water forming the elements of Galvanic 

 Action. Average of six Experiments in each case. 





Deflection of Needle. 



3 Bars of the wrought iron connected with 3 Bars of the soft cast steel, 

 ^ i) » >> ^ » >> 

 " » >> » " >> >} 



TOO degrees 

 1-30 „ 

 1-33 „ 



The wrought iron was the electro-positive metal. 



The whole of the preceding galvanometer experiments afford some compari- 

 son of the galvanic action set up by the exposure of combinations of wrought 

 iron, steel, &c, to sea-water, colliery mineral waters, or river waters, &c, of 

 known composition, and are so far interesting, because in actual practice 

 wrought and cast iron and steel bars, plates, &c, are frequently exposed to 

 similar destructive influences. 



