C. Bancs — Status of High Temperature Research. 335 



The platinum melting point merely refers to the fusion of 

 the junction of the couple and is not very reliable. Metals 

 whose boiling points show wide margins, like cadmium, are 

 found by Carnelley's interpolation methods. Troost's Se' at 

 665° is probably too low. 



5. Constants. — Applying the methods of § 3 to the air ther- 

 mometer referred to in the preceding paragraph, the following 

 mean results are available for the computation : 



= 400° C. e = 3950 microvolts. 



6 X = 600° e 1 = 6560 



& = 800° e' — 9310 



6\ = 1000° e\ = 12200 



and from low temperature work, 



6 = e 20 = — 150 



100 + 680 



200 1650 



300 2760 



The constants corresponding to these values as a whole are 



(3) . . g 2Q _|_ 45680 = 10 «.<<"6 + . 00011060 + 1()a . 8 49_.00S01^ 



Applying the same method to the data given in the above 

 table, the following values are available in addition to the low 

 temperature data just mentioned. 



6 = 357° (Hg') e = 3466 microvolts. 



x — 457° (near S') e 1 = 4690 



ff = 954° (Ag) e' =11960 



B\ = 1054° (Cu) e\ = 13585 



The constants deduced are then 



(4) . . e„ + 23376 = io 4 - 3563 + -" 002004 6> + lo =.7O84_.oo3oi _ 



Both equations (3) and (47) are given graphically in the 

 accompanying chart, the former (the lower of the two curves), 

 with all the observational data inserted. The abscissae are 

 temperatures in hundreds of degrees centigrade, and the ordin- 

 ates electromotive forces, in thousands of microvolts. Hori- 

 zontal lines drawn across the curves show the electromotive 

 forces found by special experiments for the divers melting and 

 boiling points of the metals marked on the line, the latter 

 points being distinguished by accents. For points marked JR 

 see next paragraph. 



6. Conclusion. — According as the one or the other of these 

 curves is taken, the following sets of values are reached. In- 

 terpolations are made graphically with an accuracy of a few 

 degrees. 



