Table 312 {continued). 

 ALLOYS AT LOW TEMPERATURES. 



281 



by Cailletet and Bouty at very low temperatures. The results show that the coefficient of change with temperature 

 the alloys. The resistance of carbon was found by Dewar and Fleming to increase continuously to the lowest 



ments or Miiller, Benoit, and others. Probably the simplest rule is that suggested by Clausius, and shown by these 

 temperature. This gives the actual change of resistance per degree, a constant ; and hence the percentage of change 

 approximately hold for alloys, some of which have a negative temperature coefficient at temperatures not far from 



Temperature = 



Metal or alloy. 



— 182° — 197° 



Specific resistance in c. g. s. units. 



Mean value of 

 temperature co- 

 efficient between 

 — 100° and 

 + 100° C* 



Aluminum, pure hard-drawn wire . 



Copper, pure electrolytic and annealed . 



Gold, soft wire 



Iron, pure soft wire .... 



Nickel, pure (prepared by Mond's process 

 from compound of nickel and carbon 

 monoxide) 



Platinum, annealed 



Silver, pure wire 



Tin, pure wire .... 



German silver, commercial wire 



Palladium-silver, 20 Pd + 80 Ag 



Phosphor-bronze, commercial wire 



Platinoid, Martino's platinoid with i to 2% 

 tungsten 



Platinum-iridium, 80 Pt + 20 Ir 



Platinum-rhodium, 90 Pt + 10 Rh . 



Platinum-silver, 66.7 Ag + 33.3 Pt . 



Carbon, from Edison-Swan incandescent 

 lamp 



Carbon, from Edison-Swan incandescent 

 lamp 



Carbon, adamantine, from Woodhouse and 

 Rawson incandescent lamp 



6II0 



1900 



178 



608 



2290 



.00446 



431 



375 

 578 



538 



341 

 377 

 428 



035 

 039 

 070 



025 



087 

 312 



024 



031 

 029 



This is o in the equation 7? = ^o (» + »^). as calculated from the equation a= — 2^2 ~'°'' 



200 iia 



Smithsonian Tables. 



