Table 41 . 



LINEAR EXPANSIONS OF PRINCIPAL METALS. IN MICRONS PER 

 METRE (OR MILLIONTHS PER UNIT LENGTH). 



Name of metal. 



Aluminum . . 

 Brass .... 

 Copper .... 

 Glass .... 

 Gold .... 

 Iron, cast . . . 

 Iron, wrought 

 Lead .... 

 Platinum . . . 

 Platinum-iridium^ 

 Silver .... 

 Steel, hard . . 

 Steel, soft . . . 



Tin 



Zinc 



Expansion per 

 degree C. 



20 



19 



17 



9 



IS 

 II 

 12 



28 



9 



8.7 



19 

 12 

 II 



19 

 29 



Expansion per 

 degree F. 



II. I 



10.5 

 9.4 

 5.0 



I? 



6.7 



>S-5 



5? 

 4.8 



10.S 



6.1 



10.5 

 16.1 



Smithsonian Tables. 



1 Of International Prototype Metres. 



Table 42. 



FRACTIONAL CHANCE IN A NUMBER CORRESPONDING TO A CHANCE 



IN ITS LOGARITHM. 



Computed from the formula, 



AT 



A log ;v 



ft, =: modulus of common logarithms =r 0.43429448. 



Smithsonian Tables. 



170 



I 



