THERMO-ELECTRIC PROPERTIES OF CHARCOAL AND CERTAIN ALLOYS. 333 
1 
As above <= 1914 ; and thus two points on the line of this alloy are fixed. 
The line will be found on Plate XXI. Its equation is 
y= —0268¢+ 58°11. 
The other two platinum-iridium alloys we examined also together, the 
general arrangement being such as was described in the experiments with the 
silver-palladium alloys. In this case the N wires of the alloy circuits were 
connected with the other terminal of the galvanometer than that with which 
the N wire of the M-N circuit was connected. The temperature of the beakers 
was almost uniformly 13°3° C. It rose for a short time to 13°4°. The results 
of our experiments with these wires are given in Table VII. 
TaBLeE VII. 

MN N-PtIr,, Deflections. N-PtIr,, Deflections. 
mieitstions SORT OVNI A ar 
: Observed. Calculated. Observed. | Calculated. 
+95 3o4a Cc. —163 158°7 —148 146°5 
87°3 354 144 142°8 134 136°8 
81 329°6 132 130-4 124 eer 
aia 295°4 114'8 113°6 iL) Es} 108°3 
64 2631 97°5 98:4. 93°5 94:9 
54:3 ENA 81 81:2 78:8 79°5 
45 189 66 65°6 . 65°3 6571 
39 1653 56°8 558 558 559 
34:5 147°5 50 486 49°5 49°1 
26:9 1182 36°6 312 3166 38 
23°3 103°8 31°8 31°8 32°6 32°6 
19°8 89°6 26°5 26°5 28 27-4 
i bgt 80 23 23 24 24:9 
14:3 68:3 19 18°9 19°9 19°6 
12:5 61°5 15 16°5 15:3 N72 





Table VIII. gives the observations of various deflections of the M-N 
circuit and the corresponding temperatures of the heated junction. 


Tasle VIII. 
Temperature. M-N Deflection. 
29" G. 0 
103°8 23°7 
142°2 33 
18671 44:3 


MOL, XXVIII. PART IT. 45s 
