528 



CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 



APPROXIMATE WEIGHT IN POUNDS OF RODS ONE FOOT LONG. 



APPROXIMATE WEIGHT IN POUNDS OF ALUMINUM, BRASS, COPPER, IRON, STEEL AND 



ZINC PER SQUARE FOOT. 



Aluminum (99% pure) 1.61 



Copper 1.00 



German Silver (18% Nickel) 18.00 



Gold (99.9% pure) 1.38 



COMPARATIVE RESISTANCES OF METALS. 

 (Copper as the Unit.) 



Nickel 7.78 



riatinum (annealed) 5.65 



Platinoid 20.00 



Silver (annealed) 92 



Iron . 

 Lead 



5.70 

 12.80 



Tin . 

 Zine 



8.28 

 3.62 



