U PROF HUGH L. CALLENDAK AND MR. HERBERT MOSS 



t- times as great as could be obtained in reading the difference of level on the 



gauge: 



Temperature difference 



November 2, 1908. 3 p.m. Current 7 '52 amperes. increasing. 



Box temperature observed, 2rO C. Cold side. Hot side. 



Readings of platinum thermometers 129171 1656'82 



Calibration and temperature corrections +0153 +0'228 



Corrected bridge readings, R 1291'863 1657'048 



Resistances at C., R, 1194'052 1191-657 



Differences, R-R, 97'811 465'391 



Fundamental intervals, RIOO RU 464'56 46412 



Temperatures on platinum scale, pt 2T055 100'274 



Corrections to gas scale (tpt) -0'247 + 0'004 



Temperatures t t and t t on gas scale 20'808 100'278 



Mercury gauge readings : Cold side. Hot side. 



Levels of mercury in gauge (cm. corrected) 511522 67'6196 



Upper thermometers (at 52 cm. level) 21'6 C. 21'9 C. 



Lower thermometers (at 8 cm. level) 20'95 C. 21'0 C. 



Mean temperature of columns below 51 cm 21'27 C. 21 '35 C. 



Correction for temperature difference, 0'08 C 0'0009 cm. 



Difference of level, h = 67'6196-511522 = .... 16 '4674 cm. 



Mean temperature of h, 22'0 C. Correction of A to t t . -0'0035 



Observed lengths of columns by steel tapes corrected . 192755 192'815 



Effective height, H 2 = 6^ = 1156'890 cm. dE = R 2 -R, = 0'360 cm. 



Temperature of rfH observed, 211 C. Reduction to f, negligible (0'00002 cm.). 



Corrected value of A, h' = A-0'00018 (h-dH) (-,) = IG'4630. 



Expansion f, to t t , ^fa-tj = ///(H,-//) = (T0144358. 



Mean coefficient f t to t, in terms of volume at ,, ,, = 0-Q00181645. 



To facilitate comparison between the different observations in which the cold 



*as at atmospheric temperature, the results were further reduced to a 



*mperature at 20' C. for the cold column, assuming the value of the 



\ n'r, 8 1 ^ V 1Ume at 2 - to ^ - 0001805 - The value 

 lent could be deduced, with sufficient accuracy for the purpose, from 



M of observafcons, extending from 20 C. to 187 C This reductic 

 - effected by means of formula (6), p. 9, and involves the addUi n to /' 



the 



