THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JULY 1881. 



I. Remarks on Dr. Mills's Researches on Thermometry, 

 By T. E. Thorpe, Ph.D., F.R.S., andA.W. RiJCKER,if..4.* 



A PAPER by Dr. Mills, F.R.S., entitled " Researches on 

 Thermometry," has recently been published in the Trans- 

 actions of the Royal Society of Edinburgh for 1880. We are 

 ourselves engaged in a comparison of the air- and mercurial 

 thermometers ; and therefore, when Dr. Mills was good enough 

 to send us a copy of his paper, we naturally read it with con- 

 siderable care and interest. Of the labour which he has ex- 

 pended on several difficult thermometer-corrections we cannot 

 speak too highly ; but there are a number of points concern- 

 ing which it would be desirable to have further information. 

 Some of the difficulties we have found may be due either to 

 errors, or to insufficient explanation of the terms and symbols 

 used ; and in view of the latter possibility and to avoid mis- 

 understanding, we have been compelled to discuss the very 

 simple mathematical formulas employed with what may be 

 thought excessive minuteness. Dr. Mills divides his paper 

 into six sections ; and we shall head our remarks concerning 

 any one of them by the title which he has affixed to it. The 

 sections are : — 



I. Calibration and the calibration unit. 



II. The correction for the exposed thread. 



III. The movement of the zero with (1) time and (2) 

 temperature. 



* Communicated by the Authors. 

 Phil Mag. S. 5. Vol. 12. No. 72. July 1881. B 



