42 Messrs. Paterson and Dudding on Estimation of 



Table I. — (Reduction factor = Mean spherical candle-power divided 

 by mean horizontal candle-power.) 





Watts 



Lumens 



Temperature 

 of black body 





Watts 



Lumens 



Temperature 

 of black body 

 at identity of 

 colour (Cent, 

 absolute). 



Volts. 



per mean 



horizontal 



candle. 



per 



watt. 



at identity of 



colour (Cent. 



absolute). 



Volts. 



per mean 



horizontal 



candle. 



per 



watt. 



Carbon Filament Lamp ( Hashed) No. 1. 



Carbon Filament Lamp (flashed) No. 2. 



100 volts, 16 candles. 



100 volts, 16 candles. 



Reduction Factor=0*85 5 . 



Reduction factor =0*89. 



492. 



Hl-o 



0-09- 



1,515 



65 



20' 2 



- 55 5 



1,715 



i M< 



38- 



0-28 4 



1,640 



70 



14'i 



0-80 



1,775 



1 72-7 



13- q 



0-77, 



1,755 



75 



10-, 



1-09 



1,835 



82-7 



7-9 5 



1-35 



1,865 



80 



7-7 



1-45 



1,890 



92-5 



5-0 3 



2-14 



] .960 



85 



6-l 3 



1-84 



1,935 



103-0 



3-7? 



2-85 



2,055 



90 



4-8 



2-33 



1,980 



110-0 



2-5,, 



4-14 



2,120 



100 



3-2 x 



3-43 



2,075 



1300 



l-5 6 



6-85 



2,250 



105 



2-6 



4-17 



2,120 



1350 



l-3 7 



7'7- 



2,300 



107 



2-5 2 



4-44 



2,135 



1400 



l-2 t 



8-8 5 



2,325 













Carbon Filament Lamp ( flashed) No. 4, 

 200 volts, 16 candles. 



Carbon Filament Lamp (flashed) No. 3. 



100 volts, 16 candles. 







Reduction factor =0 - 86,. 



Reduction factor =0'85. 



140 



18-., 



0-60 



1,710 



65 



19- 5 



0-55 



1,720 



150 



i2-: 



0-85 



1,770 



70 



13 8 



0-77 , 



1.775 



160 



9-0 



1-18 



1,835 



75 



lO'o 



]-06 5 



1.835 



180 



5'2 



2-09 



1.955 



80 



7-6 4 



l-40 5 



1,890 



200 



3-2 



3-41 



2,070 



85 



6-0 4 



1-77, 



1,935 



210 



2-6 



4-05 



2,120 



90 



4-8 G 



2-20 



1,985 1 



220 



22. 



4-95 



2,165 



100 



3-3, 



3-21 



2.070 



V 





105 



2-7 9 



3-83 



2,115 



Carbon Filament Lamp (unfl ashed) No. 5. 



107 



2-6 3 



4-07 



2,130 



200 volts, 16 candles. 



115 



120 



20 4 



T8 X 



5-25 

 5-91 



2,200 

 2,240 



Reduction factor=0'82 5 . 



130 



1' 4 3 



7'50 



2,310 



140 



22- 2 



0-47 



1,710 



135 



T2 



8-58 



2.345 



150 



15- 2 



0-68 



1,775 





160 



10-o 



0-95 



1,835 



Tungsten Filament Lamp (Drawn) No. 6. 

 115 volts, 30 watts. 



180 

 200 

 210 



61-4 



3-7 8 

 30 8 



1-68 

 2-74 

 3-36 



1,940 

 2,050 

 2,095 



Reduction factor =0'79. 



220 



2-5 



4-08 



2,140 



38-2 

 47-4 



21V 



11*1 



0-46 

 0-90 



1,640 

 1,755 



Tungsten Filament Lamp (Squirted) No. 8. 



57-8 



6-3 



1-57 



1,865 



105 volts, SO watts. 



68-7 



40.; 



2-47 



1,960 



Reduction factor- 78.. 



93-2 



l-9 2 



517 



2,145 



37 



14- 7 



072 



1.710 



1205 



Mo 



9-00 



2,325 



40 



ll' e 



085 



l s 74| 





45 



7'8 3 



1-26 



1,800 



Tungsten Filament Lamp (Squirted) No. 7. 



50 



6-1. 



1-62 



1,860 



105 volts, 32 watts. 



55 



4-7 3 



2-10 



1,900 



Reduction factor =0'79. 



60 

 65 



3-7 s 

 30, 



2-61 



3-28 



1,960 

 2,010 



38-8 



15v 



063 



1,640 



70 



2-6: 



3-81 



2,055 



48-2 



93 4 



] 06 



1,755 



75 



2-2 



4-47 



2,095 



57'2 



5-4 x 



1-84 



1,865 



80 



1-9* 



5-21 



2,135 



67 



35 8 



2-78 



1,960 



90 



1*4. 



665 



2,215 



90-5 



1"7 6 



566 



2,145 



100 



1*2 



819 



2,285 



1170 



1-0- 



9-54 



2,325 



105 



l-0 9 ° 



9 06 



2,320 



