THERMO-ELECTRIC PROPERTIES OF CHARCOAL AND CERTAIN ALLOYS. 339 
Table XII. contains deflections of the M-N circuit and corresponding 
temperatures of the heated junction of that circuit. 


TABLE XII. 
Temperatures, M-N Deflection. 
| 
13-4 0 
88°7 17 
180°5 38°6 
1979 42°75 
202°2 td 
Thus do, = const. + ‘23496¢, 
dé, . 
and ae 23496 ; 
do . ; dé . : : 
and therefore is determined for two temperatures. e is here the ratio of 
1 1 
the length of the particular line of temperature intercepted by the Pd and alloy 
lines to that intercepted by the M and N lines. The line of PtAg;,; will be 
found on Plate X XI. It will be noticed that the accuracy of this line depends 
on the accuracy of the palladium line. If the latter should be found not quite 
accurate, and be changed in position, the PtAg,; line must be drawn from 
it in its new position. The equation to the line of this alloy is found to be 
y=—'241¢—40°93. It lies much lower on the diagram than the lines of its 
constituent metals. 
Magnesium-Thallium Alloy, containing 25 to 50 per cent. of Thallium. 
This alloy was furnished to Professor Tarr by Dr Gore. We joined a wire 
of it in circuit with the N wire. The ends of the N wire in both circuits were 
joimed to the same terminal of the galvanometer. The temperature of the 
beakers varied from 13°4° to 13:55° C. The observations are contained in 
Table XIII. 
TABLE XITI. 



MLN MeTI-N Deflections. 
cdections Temperature. 
; Observed. Calculated. 
+ 180 394-1" C. — 360 356'3 
169°7 372°4 336 3346 
157-7 347°3 309 309°8 
1485 327°5 290°5 290°3 
138°7 306°8 269 2701 
129-7 287°8 248 251'8 
121 269°3 236 234 

