328 Table 401. 



CONDUCTING POWER OF ALLOYS. 



This table shows the conducting power of alloys and the variation of tlie conducting power with temperature.* The 



values of C^ were obtained from the original results by assuming silver = — 5- mhos. The conductivity is taken 



as C,=: C„ (i — at-\-bfi\ and the range of temperature was from 0° to 100° C. 



Tht table is arranged in three groups to 8how(i) that certain metals when melted together produce a solution 



which has a conductivity equal to the mean of the conductivities of the components, (2) the behavior of those 



metals alloyed with others, and (3) the behavior of the other metals alloyed together. 



It is pointed out that, with a few exceptions, the percentage variation between o^ and 100"^ can be calculated from tha 



tormula P ^=^ P ^ -^ where/ is the observed and /' the calculated conducting power of the mixture at 100° C, 

 and P. is the calculated mean variation of the metals mixed. 



Alloys. 



Weight % Volume % 



of first named. 



Co 



aXio8 



^X io« 



Variation per 100° C. 



Observed. Calculated, 



Group i. 



SnePb 



Sn4Cd 



SnZn 



PbSn 



ZnCd2 



SnCdi 



CdPbs 



77.04 

 82.41 

 78.06 

 64.13 

 24.76 

 23-05 

 1-2>1 



83.96 

 83.10 

 77.71 



5341 

 26.06 

 23.50 

 10.57 



7-57 

 9.18 



10.56 

 6.40 



16.16 



5.78 



3890 

 4080 

 3880 

 3780 

 37S0 

 3850 

 3500 



8670 

 1 1870 

 8720 

 8420 

 8000 

 9410 

 7270 



30.18 

 28.89 

 30.12 

 29.41 

 29.86 

 29.08 

 27-74 



29.67 



30-03 

 30.16 

 29.10 

 29.67 



30-25 

 27.60 



Group 2. 



Lead-silver (Pb2oAg) 

 Lead-silver (PbAg) 

 Lead-silver (PbAga) 



Tin-gold (Snx2Au) 

 " " (SnsAu) 



Tin-copper 



Tin-silver . 



Zinc-copper 



95-05 

 48.97 



32-44 



77-94 

 59-54 



92.24 



80.58 



12.49 



10.30 



9.67 



4.96 



1-15 



91.30 

 53-85 



36.70 

 25.00 



16.53 

 8.89 

 4.06 



94.64 

 46.90 

 30.64 



90.32 

 79-54 



93-57 

 83.60 

 14.91 



12.35 



11.61 



6.02 



1.41 



96.52 

 75-51 



42.06 

 29.45 

 23.61 

 10.88 

 5-03 



5.60 



8.03 



13.8b 



5.20 

 3-03 



7-59 

 8.05 



6.41 



7.64 



12.44 



39-41 



7.81 

 8.65 



13-75 

 13-70 

 13-44 

 29.61 

 38.09 



3630 

 i960 

 1990 



3080 

 2920 



3680 



3330 



547 



666 



691 



995 

 2670 



3820 

 3770 



1370 

 1270 

 1880 

 2040 

 2470 



7960 

 3 '00 

 2600 



6640 

 6300 



8130 

 6840 



294 

 1 185 



304 



705 



5070 



8190 

 8550 



1340 

 1240 

 iSoo 



3030 

 4100 



28.24 

 16.53 

 17-36 



24.20 

 22.90 



28.71 

 26.24 

 5.18 

 5-48 

 6.60 

 9.25 

 21.74 



30.00 

 29.18 



12.40 

 11.49 

 12.80 

 17.41 

 20.61 



19.96 



7-73 

 10.42 



14.83 

 5-95 



19.76 

 14-57 

 3-99 

 4.46 

 5.22 

 783 

 20.53 



23-31 

 11.89 



11.29 

 10.08 

 12.30 

 17.42 

 20.62 



Note. — Barus, in the " Am. Jour, of Sci." vol. 36, has pointed out that the temperature variation of platinum 

 alloys containing less than 10% of the other metal can be nearly expressed by an equation y ■=. — — nt, where y is the 



temperature coefficient and jr the specific resistance, ni and n being constants. If a be the temperature coefficient at 



0° C and s the corresponding specific resistance, s (a.-\- m) = n. 



For platinum alloys Barus's experiments gave /« =: — .000194 and «:= .0378. .f 



For steel m =: — .000303 and « = .0620, i 



Hatthiessen's experiments reduced by Barus gave for 1 



Gold alloys m ■=. — .000045, « = .00721. I 



Silver »? = — .000112, «=: .00538. I 



Copper" ttf=. — .000386, n^. 00055. I 



• From the experiments of Matthiessen and Vogt, " Phil. Trans. R. S." v. 154. 

 t Hard-drawn, 



Smithsonian Tables. 



