46 Messrs. Holman, Lawrence, and Barr on the 



point of gold, there is room for differences of opinion. The 

 claims of the work of Holborn and Wien, supported to some 

 extent bj considerations advanced by Barns*, lend much 

 weight to the conclusion that ViohVs value of 1035° is con- 

 siderably too low. Granting this, and in the absence of 

 sufficient basis for the assignment of weights to the work of 

 divers other investigators, the simplest and best step seemed 

 to be to adopt provisionally, without modification, Holborn 

 and Wien's value, 1072°. 



These two points settled upon, the constants m and n could 

 be computed as elsewhere described, and the equation trans- 

 posed to deduce other values of t from observed values of 2$<\ 

 Representing mr™ by /9, a constant, the equation for the tem- 

 perature as a function of lf e takes the form 



=v"H 



^-273°, 



which is, of course, easily solved by logarithms. 



The data given in Table I. yieid the values m = O3901, 

 n = 1*488, ft = 1645, in international microvolts and degrees 

 Centigrade,, so that 



2^=0-3901 t 1 ' 488 - 1645, or * = l-488 \ / Sf± l645 070 



From these the temperatures of column 6 have been com- 

 puted. 



The constants of the logarithmic formula have been com- 

 puted from the same data for sulphur and gold, the method 

 being sufficiently obvious. The equation becomes 

 2* e = 2-49655 t l ' 25m . 



The corresponding melting- and boiling-points are given in 

 Table I. column 7. 



^ Substitution of the same data in the Avenarius equation 

 yields 



X^ = fc-O{9-7335 + 0-0048449(f A + g}. 



The corresponding melting- and boiling-points are given in 

 column 5. 



Provisional Values of Melting -^ 

 In the paper referred to it was shown, 1st, that the loga- 

 rithmic expression fitted the Barus comparisons of the irido- 

 platinum couple with the air thermometer within the limits 

 400° to 1200° 0. with no sensible systematic error ; 2nd, that 



* Am. Jour. Sci. xlviii. p. 336. 



