270 PROCEEDINGS OF THE AMERICAN ACADEMY 



that found for this end before; but for end no. 2, a conductivity 

 about 6°f greater than previous observations showed. 



Chemical analysis of borings from the nickel bar showed the 

 following composition : — 



Nickel 85.44% 



Iron 7.56 



Silicon 0.42 



with small quantities of antimony, arsenic, copper, manganese, 

 phosphorus, sulphur, and tin. 



Analysis of borings from the gun-iron bar showed : — 



Carbon (total) 3.64% 



Phosphorus 0.59 



Silicon 1.33 



