214 Prof. H. L. Callendar on Platinum. Thermometry. 



Table II. — Table of Reduction for Dewar and Fleming's 

 Standard Platinum Thermometer. 



pt (°C). 



D'. 



f(°0.). 



i 

 dt/dpt. 



t-t'. 

 00 



*(°C.) 

 +100 



Dickson. 

 + 99-85 



+ 100 







+ 100 



1024 



+ 50 



-061 



+4939 



1-000 



-0-08 



+49-31 



+49-47 



+ o 











•976 





 +0-03 





 - 9-70 



+ 0-20 

 - 9-51 



- 10 



+0-27 



- 9-73 



•971 



- 20 



+0-58 



-19-42 



•966 



+0-05 



-19-37 



-19-18 



- 30 



+0-95 



-29-05 



•961 



+0-08 



-28-97 



-28-81 



- 40 



+ 1-36 



-38-64 



•956 



+0-11 



-38-53 



-38-39 



- 50 



+ 1-82 



-48-18 



•951 



+0-14 



-48-04 



-47-92 



- 60 



+233 



-57-67 



•947 



+0-17 



-57-50 



-57-42 



- 70 



+2-89 



-67-11 



•942 



+0-19 



-66-92 



-66-83 



- 80 



+3-50 



-76-50 



•937 



+0-22 



-76-28 



-76-25 



- 90 



+4-15 



-85-85 



•932 



+0-23 



- 85-62 



-8561 



-100 



+4-86 



-95-14 



•927 



+025 



-94-89 



-94-92 



-110 



+ 560 



-104-4 



•922 



+0-26 



-104-1 



-104-2 



-120 



+ 641 



-113-6 



•917 



+0-26 



-113-3 



-113-4 



-130 



+ 7-28 



-122-7 



•912 



+0-25 



-122-5 



-122-6 



-140 



+ 8-14 



-131-9 



•907 



+0-24 



-131-6 



-131-7 



-150 



+ 912 



-140-9 



•903 



+ 0-22 



-140-7 



-140-8 



-160 



+ 10-1 



-149-9 



•898 



+0-19 



-149-7 



-149-8 



-170 



+ 11-2 



-158-8 



•893 



+0-16 



-158-6 



-158-8 



-180 



+ 123 



-1677 



•888 



+0-11 



-167-6 



-167-8 



-190 



+ 134 



-176-6 



•883 



| +0-05 



-176-5 



-176-7 



-200 



+ 14-6 



-185-4 



•878 



! -002 



I. 



-0-09 



-185-4 

 -1943 



-185-5 

 -194-3 



-210 



+ 15-8 



-1942 



•874 



-220 



+17-1 



-202-9 



•869 



-0-20 



-203-1 



-203-1 



-230 



4 18-4 



-211-6 



•864 



-0-31 



-211-9 



-211-8 



-240 



4-198 



-220-2 



•859 



| -0-43 



-220-6 



-220-5 



-250 



+21-3 



-228-7 



•855 



1 -0-58 



-229-3 



-229-1 



-260 



+22-8 



-237-2 



•850 



! -0-73 



-237-9 



-237-7 



-270 



+24-3 



-245-7 



•845 



-0-90 



-246-6 



-246-3 



-280 



+25-8 



-254-2 



•840 



-108 



-255-3 



-254-8 



-283 



+26-4 



-256-6 





-1-16 



-257-8 



-257-3 



The above table affords a good illustration of the point 

 already mentioned, that the results obtained from the two 

 differ en ce-fornmlse (D) and (D') agree so closely over a limited 

 range, as in the present case, that it is often quite immaterial 

 which of the two is used for purposes of reduction. The 

 largest difference over the experimental range in the present 

 instance is only 0°"3, which is less than many of the errors of 

 observation, except at the fixed points and under the most 

 favourable conditions. In comparing the two formula the 

 following expression for the difference between them is 

 occasionally useful : — 



D-D / =^-^'=^D(2^ + D-100)/10,000+(^'-l)D / . 



