Heat and Light from Heated Solid Bodies, 565 



the surface, in square centimetres, of the strip between the 

 potential leads EE, the absolute amount of energy lost by 

 the strip per square centimetre per second is found. This is 

 equal to AV/4"2S, and is shown for all the experiments in 

 Column 10. The figures in Column 10 represent the number 

 of gramme- water- degree-centigrade-units of radiant energy 

 lost per second from each square centimetre of surface of the 

 strips. 



Table of Results. 



No. of 

 Expt. 



Condition. 



Strip. 1 



Amps. 



Volts. 



101 



2-81 



Ohms. 



Watts. 



Watt- 

 ratio. 



Temp. 



AV/JS. 



1. 



Gray light. 



Bright- 

 Black. 



1-9 

 5 35 



0-532 

 0-525 



1-922 

 15-09 



7-85 



435° 

 452 



0417 

 0-327 



2. 



j> 



Bright. 

 Black. 



2-13 

 5-9 



1-175 

 323 



0-552 

 0-547 



2-5 

 19-05 



7-62 



465 



487 



00543 

 0-414 



M 



Very dull "I 

 red. J 



Bright. 

 Black. 



231 

 6-2 



1-32 

 345 



0572 

 0-557 



3-05 

 21-4 



7-02 



495 

 503 



0-0662 

 0-465 



4. 



u 



Bright. 

 Black. 



2-34 

 6-25 



1-43 

 3-7 



0611 

 0592 



3-31 

 23-1 



698 



550 

 560 



0-0727 

 0-50 L 



5. 



Dull red. 



Bright. 

 Black. 



2-8 



7-2 



1-74 

 4-32 



0-622 

 0600 



4-87 

 31-1 



6-53 



573 

 573 



0106 

 0676 



6. 



j> 



Bright. 

 Black. 



304 



7-7 



1-975 



4-77 



0-650 

 0-620 



6-0 

 368 



613 



613 

 607 



0-1302 

 0-799 



7. 



» 



Bright. 

 Black. 



32 



8-0 



2-1 

 5-05 



0-656 

 0-632 



6-72 

 404 



602 



623 

 625 



0-146 



0-877 



8. 



Fair red. 



Bright. 

 Black. 



35 



8-5 



2-37 

 5-47 



0-677 

 0644 



8-3 

 46-5 



5-6 



655 

 643 



0-180 

 101 



9. 



Good red. 



Bright. 

 Black. 



4-0 

 9-45 



2-79 



632 



0-697 

 0-670 



11-15 

 59-7 



536 



685 

 685 



0-242 

 1-296 



10. 



Bright red. 



Bright. 

 Black. 



4-62 

 104 



3-35 



7-24 



0-724 

 0696 



15-45 



75-2 



4-87 



727 

 727 



0-335 

 1-632 



»•{ 



Very bright 1 

 red. J 



Bright. 

 Black. 



5-3 

 11-6 



4-1 



8-52 



0-773 

 0-735 



21-7 

 98-9 



4-56 



800 

 793 



0-472 

 2-147 



12. 



>» 



Bright. 

 Black. 



5-99 

 12-75 



48 

 9-85 



0-801 

 0-772 



28-7 

 125-6 



4-38 



843 

 848 



0-623 

 273 



13. 



Nearly white. 



Bright. 

 Black. 



6-4 

 13-2 



5-35 

 10-5 



0-836 

 0-796 



34-2 

 138-7 



4-06 



898 

 891 



0742 

 301 



Column 7 gives the power in watts supplied to each 

 strip, i. e. the product of the current into the P.D. between 

 the points EE. Column 8 gives the ratio of the watts used 

 by the dull strip to the watts used by the bright one, both 

 being matched in appearance, and both being practically at 

 the same temperature, as is shown by the numbered experi- 

 mental points on No. 1 curve lying so nearly on the same 

 ordinates as the corresponding points on No. 2 curve. 



