Hydrometers of Total Immersion. 513 



from l°to 1°"5 higher than that of the water. The correction 

 for exposed stem, which certainly does not amount to 0°'00L, 

 is neglected. 



Zero corresponding to prolonged exposure at 



0° calculated from the formula given in 



Appendix C is +0-097 



The depression which corresponds to 25° is . — 0*023 



Zero corresponding to 25° is -f Q'074 



Barometric pressure reduced 756'4 



189 mm. water-pressure = mercury .... 13*9 



Total pressure 77Q-3 



Uncorrected reading of temperature 



C Calibration 



r< ,. J External pressure 



Corrections < T , i r 



i Internal pressure 



(Zero .... 



Reading reduced 



Correction for fundamental interval . 



Temp, in scale of a mercury thermometer 

 Reduction to a thermometer of hydrogen 



Temp, in scale of a hydrogen thermometer 



25-098 

 -0-030 



-o-ooi 



+ 0-030 

 -0-074 



25-023 



+ 0-005 



25-028 

 -0095 



24-933 



Calculation of Results. 



The weight in vacuo of the hydrometer is 160*21506 g. 

 The weight in air of the platinum added is 1-40483 g. 

 which, as the standard weights are of brass, would in vacuo be 

 1-40471 g. 



The volume of the platinum at 24° # 933 would be 



_ 1-40471 (1 + 0-0000266 x 24-933) 

 21-45 



= 0-06553 c.c. 



The specific gravity of water at 24°-933 is 09970886, 

 Hence /9u = 0-9970886x 0-06553=0-06534. 



v _ W + M- — pV 

 P 



161-55443 ir ., n . 9rir 

 = 0^99708^ =16202615 - 



