E. Merritt — Light from Incandescent Lamps. 175 



measured in Watts ; L is the energy of the light, also meas- 

 ured in Watts ; and C. P. is the candle power. 



Lamp B. 

 An Edison 16 C. P. Lamp. Resistance 



249 ohms. 











L 



L 



E. M. F. 



W. 



G. P. 



L. 



W 



cTp.' 



63-0 



25-4 



0-3 



0-42 



0-016 



1-61 



74-6 



37-8 



1-0 



0-77 



•021 



0-79 



85-4 



52-5 



2-5 



1-96 



•037 



0-78 



99-0 



72-2 



6-3 



4-30 



•059 



0-68 



116-0 



102-0 



15-2 



7-38 



•072 



49 



Lamp C. 

 "Weston 16 C. P. Cold resistance = 402 ohms. 











L 



L 



E. M. F. 



W. 



C. P. 



L. 



W 



cTpV 



72-0 



21-6 



0-4 



0-46 



0-021 



1-27 



87-4 



33-5 



1-5 



1-10 



•033 



0-76 



102-0 



47-8 



4-4 



2-09 



•044 



0-48 



117-0 



66-1 



10-7 



3-19 



•048 



0-30 



Lamp D. 

 Weston 16 C. P., 70 volt. Resistance = 152 ohms. 











L 



L 



E. M. F. 



w. 



C.P. 



L. 



W 



cTp." 



43-0 



25-8 



0-5 



0-53 



0-021 



1-06 



50-7 



36-0 



1-6 



0-97 



•027 



0-62 



60-5 



520 



5-2 



2-03 



•039 



0-39 



67-5 



65-5 



11-0 



395 



•060 



0-36 



, Lamp E. 

 Bernstein 8 C. P. Resistance = 11 "3 ohms. 



E. M. F. 



W. 



C.P. 



L. 



L 



W 



L 



cTp.' 



12-2 



25-2 



0-2 



0-20 



0-008 



1-00 



13-4 



308 



0-5 



0-41 



•013 



0-84 



15-0 



40-4 



1-3 



0-75 



•018 



057 



16-4 



53-2 



4-1 



2-03 



■038 



050 



The curves of light energy, L, and total energy, W, for 

 these four lamps are shown in fig. 3. 



None of the lamps tested were of the most recent styles, all 

 being made previous to 1886. All of the lamps, also, except 

 lamp A, had been used a greater or less time before the tests 

 were made. Lamps B and E especially had seen a great deal 

 of use, and had their glass globes slightly blackened. 



