Isometrics of Liquid Matter. 



353 



Table VII. — Comparisons of Thermocouple and Air- 

 thermometer. 



V= 239-93 cub. centim.; t>' = '030cub. centim.; t/'=-694 cub. 

 centim. ; h = 48*28 centim. 



Time. 



T M . 



Nfl. 



v 



Diff. 



Time. 



T M - 



N* 



sv 



Diff. 



h m 



°C. 



o 



°c. 



°0. 



h m 



°C. 



o 



°c. 



°c. 



53 



299-6 



30-147 



305-0 



-5-4 



4 18 



122-5 



9-629 



123-4 



-0-9 



1 05 



295-3 



29-261 



301-2 



-5-9 



4 29 



117-2 



9077 



118-0 



-0-8 



1 16 



292-0 



29-175 



297-3 



-53 



4 38 



113-1 



8-696 



114-3 



-1-2 



1 25 



289-1 



28-836 



294-8 



-5-7 



4 52 



107-1 



8-086 



108-0 



-0-9 



1 33 



236-3 



22-355 



241-2 



-4-9 



5 29 



940 



6-717 



940 



+0-0 



1 42 



232-2 



21-814 



236-5 



-4-3 



5 39 



90-9 



6-430 



91-0 



+0-1 



1 55 



226-9 



21-179 



231-0 



-4-1 













2 09 



222-0 



20-597 



225-8 



-3-8 













3 03 



167-7 



14-549 



171-2 



-3-5 



rie 



1000 



7-313 



100-1 



-o-i 



3 13 



160-9 



13-794 



164-1 



-3-2 



*\ 28 



100-1 



7-329 



100-3 



-0-2 



3 24 



153-4 



12-911 



155-6 



-2-2 



[37 



100-1 



7-207 



100-1 



+0-0 



3 36 



145-4 



12-076 



147-7 



-2-3 













* Comparisons in steam. 



Series of this kind show at once that throughout every stage 

 of cooling the temperature registered by the thermocouple is 

 persistently higher than the corresponding temperature of the 

 air-thermometer. Inasmuch as the system cools from the 

 outside of the thermometer-bulb, this may be regarded as a 

 mere indication of too rapid cooling. I must note, however, 

 that by retarding or accelerating cooling, I did not materially 

 change this discrepancy. Hence, without passing further 

 judgment, I deduced both T a ^ and T t)C , for all the observations 

 below. 



37. After correcting the temperature in the manner stated, 

 I obtained the data for the five isometrics given in Table VIII. 

 Temperatures a ,t and t , c axe measured by the air-thermo- 

 meter and the thermocouple respectively. Two data under A0 

 are to be similarly interpreted. Ap is defined above, § 33. 

 Slight irregularities of 6 still appear, showing that if tempera- 

 ture is to be measured by the torsion-galvanometer, check 

 readings of the boiling-point of water must be made before 

 and after each series of temperature observations. Two 

 independent series are usually given for each substance. 



