Correction of the Gas- 2 her mo meter. 85 



The values of the scale-correction for the monatomic gases 

 given in Table XI. are calculated by the following formulae : — 



Constant-Pressure, dt= {0'1U5 */100-l + (0 o /#) °' 5 ) Copo/R, 

 Constant- Volume, ^ = (-0*1689 t/100 - 1 + (^/6> ) " 5 )c ^o/R. 



Table XI. 

 Scale-Correction for Monatomic Gases. 





Constant-Pressure, 7C 



cms. 



Constant- Volume. p n = 100 cms. 



Temp, 

 cent. 





























Krypton. 



Argon. 



Helium. 



Krypton. 



Argon. 



Helium. 



o 

 —250 







+0-557 







o 

 -•101 



—200 







+ 



•173 





- ; i94 



-•051 



; -150 





+•278 



+ 



•073 



- -L56 



-•101 



-•0265 



-100 



+ : 175 



+ •114 



+ 



•0298 



- -072 



-•047 



-•0123 



j ~ m 



+ -053 



+ •034 



+ 



•0091 



- -0242 



-•0157 



-•0041 



— 20 



+ -0155 



+ •0101 



+ 



•00265 



- -0070 



-•0045 



-•00120 



, - 10 



+ -0069 



+ •0045 



+ 



•00118 



- -0031 



-0020 



-•00053 



; 4- 10 



- -0052 



-•0034 





•00089 



+ -0027 



+•0017 



+•00045 



; + 20 



- -0093 



-•0060 



— 



•00159 



+ -0045 



+ •0029 



+•00077 



+ 30 



- '0116 



-•0075 



— 



•00198 



+ -0058 



+•0038 



+•00098 



+ 40 



- -0130 



-•0084 



— 



•00222 



+ -0064 



+ •0041 



+ •00109 



' + 50 



- -0130 



-•0084 



— 



•00222 



+ -0065 



+ •0042 



+•00113 



i + 60 



- -0124 



-•0080 



— 



•00212 



+ -0062 



+•0040 



+•00106 



! 4- 70 



- -0105 



-•0068 



— 



•00180 



+ -0056 



+•0036 



+•00095 



j + 80 



- -0078 



-•0051 



— 



•00133 



+ -0041 



+ •0027 



+•00070 



! + 90 



- -0042 



-•0027 



— 



•00072 



+ -0021 



+•0014 



+•00035 



+150 



+ -0315 



4 -0204 



+ 



•0054 



- -0180 



-•0116 



-•00306 



i +200 



+ -075 



+•049 



+ 



•0128 



- -045 



-•029 



-•0076 



! +300 



+ -194 



+•126 



+ 



•0332 



- -119 



-•077 



-0203 



+450 



+ -415 



+•269 



+ 



•071 



- -275 



-•178 



-•0468 



I +1000 



+ 1-42 



+ •92 



+ 



•243 



1 



-1-09 



-•71 



-•187 



It will be observed that the correction is negative for the 

 constant- volume thermometer at temperatures below 0°C. 

 According to Travers (loc. eit.) the helium thermometer reads 

 o, l above the hydrogen thermometer at the boiling-point of 

 oxygen, and 0°*2 above at the boiling-point of hydrogen. 

 The hydrogen correction is opposite in sign, and nearly equal 

 in magnitude. The true values of the boiling-points, obtained 

 by interpolating between the hydrogen and helium values, 

 would be 



Oxygen B.-P. 90°*13 Abs. Hydrogen B.-P. 20°-31 Abs. 



