276 



Drs. J. T. Bottomley and J. C. Beattie. 



Table IL— June 17, 1897. Two Platinum Wires, Pto and Pt4, length 

 39*2 em., diameter 0*025 cm., from the same hank of wirej Pt3 

 bright, Pt4 sooted. 



Ph 



S 



eS 



.5 



c 



<v 



6 







Pressure in millimetres. 



c 



o 



'/J 



Temperature. 



Thermal energy 

 lost per square 

 centimetre per 

 1 second. 



Resistance in 

 ohms. 





bc s * 

 0) pi 



(b CO _2 



tt ^ ^ o 



(U 03 o 



f- O <U 



'0245 



1 -94 



15 



-9004 



X 10"^ 



1-94 



15 



-9004 X 10"* 



-00040 



•0819 



2-03 



41 



10-53 







1-984 



26 



10-29 







-00040 



'1888 



2 -27 



120 



48 -09 







2-050 



47 



42 -52 







-00025 



•2348 



2-466 



190 



105 -1 







2-134 



74 



89 -00 







-00033 



-3003 



2-602 



243 



181-4 







2-224 



109 



155-1 







-00025 



"3822 



2-781 



318 



314 -2 







2-314 



135 



261-5 







-00025 



-4586 



2-900 



377 



473 -1 







2-399 



166 



390^2 







-00025 



-5405 



3 -039 



445 



686 -7 







2-492 



200 



563 -0 







-00025 



-6470 



3-196 



538 



1034-0 







2-610 



245 



844 -7 







-00016 



-8479 



3-418 



719 



] 902 -0 







2-788 



321 



1552-0 







-00025 



1 -0230 













2-919 



383 



2362 -0 







-00050 



1-1696 













3 -033 



442 



3209 •O 







-00130 



1-462 













3 -228 



560 



5338-0 







-0019 



1 -608 













3-331 



637 



6658 -0 







-0025 



1-754 













3 -424 



726 



8149 -0 







-0023 



Tables III, IV, V, showing the Amount of Thermal Energy lost per 

 sq. cm. per second by each of two precisely similar Platinum Wires 

 at the same temperature, one of the wires having a Bright Metallic 

 Surface and the other being Lightly Sooted. 



Table III. 



Pti and Pt2. Diameter of Wire, 0*0542 cm. 



Temperature. 



Energy lost by 

 bright wire. 



Energy lost by 

 sooted wire. 



Ratio 

 sooted/bright. 



200 



1-1 



5-3 



4-8 



250 



1-8 



8-9 



4-9 



300 



2-7 



12-8 



4-7 



350 



3-8 



19-8 



5-2 



400 



4-9 



26-1 



5-3 



450 



6-2 



33-3 



5-4 



500 



7-9 



42 -0 



5-3 



550 



10 -0 



50-0 



5-0 



600 



11-9 



58-5 



4-9 



650 



13-8 



68-7 



5-0 



