438 A. L. Day and J. K. Clement — Gas Thermometer. 



Expansion. 





Date 



Corrected 

 Temperature 



a/L 



Obs.— Cal. 





Observed 



Calculated 



Dec. 



30, 1907-.- 



287-7° * 



•002635 



•002661 



-26 







511*2 



•004871 



•004879 



— 8 





• 



712-9 



•007051 



•006994 



+ 57 



Dec. 



31, 1907-.. 



700-0 



•006878 



•006855 



+ 23 







866-6 



•008653 



•008677 



— 24 



Jan. 



2, 1908 



504-0 



•004812 



•004805 



+ 7 







504-4 



•004813 



•004810 



+ 3 







690-0 



•006763 



•006748 



+ 15 







689-4 



•006755 



•006742 



+ 13 







856-5 



•008600 



•008565 



+ 35 







856-4 



•008610 



•008564 



+ 46 







1044-1 



•010616 



•010699 



— 83 







1043-8 



•010635 



•010695 



— 60 



X _ total expansion 

 L ~~ initial length 



Equation used for the "calculated" 

 expansions, A=(8S69'5£ + 1'3192£ 2 )10- 9 



In Furnace II. 

 Temperature Distribution along the Bar. 



Left 



Middle 

 (Corrected 



Eight 















12 cm 



10 em 



5cm 



Temperature) 



5 cm 



10 cm 



12 cm 



— 13° 



- 1° 



0° 



294-0° 



-4° 



-12° 



-27° 



-22 



- 6 



_ 2 



392-0 



— 6 



— 20 



-41 



— 28 



— 9 



— 4 



491-0 



+ 2 



-17 



— 33 



— 30 



— 13 



— 5 



592-5 







— 10 



— 30 



— 34 



— 15 



— 5 



695-0 



+ 4 



- 3 



-27 



— 35 



— 17 



— 7 



795-0 



' +8 



+ 4 



-17 



— 52 



— 21 



— 9 



894-0 



+ 9 



+ 6 



— 12 



— 51 



— 21 



— 10 



994-0 



+ 8 



+ 8 



— 14 



* Inasmuch, as the expansion-cofficient which is here being determined 

 itself enters into the determination of the temperature, the two quantities 

 are not independently variable. The temperatures given above are, there- 

 fore, based upon tentatively assumed constants which have been chosen 

 about where the final values were expected to come. The assumed data are 

 these : 



Zinc melting point 419° 



Silver " " 960 



Copper " " 1083 



With actual temperatures 1° higher or lower, the expansion coefficient 

 would not be affected by an amount equal to one-tenth of one per cent in 

 any part of the curve. The assumed values are, therefore, amply exact for 

 the purpose. 



