High Temperatures by the Method of Colour Identity. 43 

 Table I. — continued. 



Volts. 



Watts 



Lumens 



per mean 



per 



horizontal 



watt. 



candle. 





Temperature 

 of black body 

 at identity of 

 colour (Cent, 

 absolute). 



Tungsten Filament Lamp {Squirted) No. 9- 

 105 volts, 60 ivatts. 



40 



45 



50 



55 



60 



65 



70 



75 



80 



00 



100 



105 



110 



115 



120 



125 



130 



135 



KeducOon factor =078- 



12' 8 



9-8, 

 7'3 4 



5-7 

 4-5.3 



3i 



2 6, 



').-) 



I?, 

 1'3 9 

 12- 



M 4 

 10 4 



094- 

 0-88. 

 0-S2 

 076 



0-77, 



1-01 



1-35 



1-74 



2-18 



2-67 



317 



3-73 



437 



5-70 



712 



8-06 



8 66 



9-51 



104 



11-2 



121 



1 13-0, 



1,710 

 1,775 

 1,835 

 1,880 

 1.020 

 1.970 

 2.015 

 2,055 

 2,100 

 2,175 

 2.245 

 2,280 

 2,315 

 2,340 

 2,375 

 2,395 

 2,435 

 2,460 



Tungsten Filament Lamp (Drawn) Xu. 11, 

 200 volts, 20 waits. 



80 

 90 

 100 

 110 

 120 

 130 

 140 

 150 

 160 

 180 

 200 

 210 

 220 



Reduction factor = 078- 

 13-- 

 97 



-- 

 5-5 



l i 

 3-5 s 



30 t 



2-5-, 

 21 8 

 1-T l 

 1-3 S 

 12, 



1 0-73 



1 -02 



1-36 



1-S0 



223 



2-75 



328 



387 



4"4 a 



5-8, 



7-2. 



79 



8-6 6 



1,720 

 1,770 

 1,835 

 L.885 

 1,935 

 1 .970 

 2,020 

 2,060 

 2,105 

 2.170 

 2.24.*) 

 2,270 

 2,320 



Volts. 



Watts 



Lumens 



per mean 



horizontal 



candle. 



per 



watt. 



Temperature 

 of black body 

 at identity of 

 colour (Cent, 

 absolute). 



Tungsten Filament Lamp (Drawn) No. 10. 

 100 volts. 15 watts. 



Reduction factor = 0" 



45 



50 



55 



60 



Qj 



70 



75 



80 



90 



100 



105 



110 



115 



120 



125 



130 



135 



8-6 



6'lg 



4-8, 

 3-8 s 

 32, 

 2-6,. 

 2*2 



l'9g 



l-5 

 1-2, 



I'll 

 10 



0-91- 

 0-83. 

 0-77 5 



072,, 

 066, 



117 



1-59 

 205 

 255 

 3-09 

 371 

 4-36 

 5-10 

 675 

 813 

 902 

 9-88 

 10-8, 



us: 



127 



137 3 



14-8, 



1,800 

 1,860 

 1,915 

 1,960 

 2,015 

 2,055 

 2,105 

 2,140 

 2,225 

 2,290 

 2,325 

 2,360 

 2,400 

 2,430 

 2,455 

 2,485 

 2,505 



Tungsten Filament Lamp (Drawn) Xu. 12 

 230 volts, 60 watts. 



Reduction factor=0"78- 



100 

 110 

 120 

 130 

 140 

 150 

 160 

 170 

 180 

 190 

 210 

 230 

 240 

 260 



9-5 



T04 



1.770 



7'b 5 



1-34 



1,825 



5-7 



174 



1,870 



4'5 4 



217 



1,915 



3'8 



260 



1,960 



3-1 



310 



2.000 



2'7 4 



360 



2,040 



23 



41 , 



2,080 



2-0, 



4 ^, 



2,110 



l-8j 



5*4 



2,145 



1-4. 



B'7 a 



2,210 



12 



80, 



2.270 



H, 



8-7., 



2,31 >5 



0-96 



10*2 



2.360 



In obtaining the higher temperature values for plotting on 

 fig. 3, it is very useful to make use of a "watt-temperature" 

 curve. The carbon lamp, for instance, cannot with safety 

 be run for long periods at temperatures in the region of 

 2000° C. If the watts be plotted against temperatures 

 obtained by the identity of colour method the resulting 

 curve will be found to be a logarithmic one, and no devia- 

 tion whatever can be detected from such logarithmic over 



