of Thermal Conductivity and Emissivity. 



Setl. 



Set II. 



291 

 Set III. 



Conductivity 

 (from 1st sine term). 



[•2407] 



•2507 



•2541 



Emissivity: — 

 From " a" term. 

 „ 1st sine term. 



•000321 

 •000397 



•000331 

 •000403 



•000319 

 •000405 



Set II. is probably the best of the three. 



Rod II. (^ inch). — Diam. = *6426 cm. Density = 8*47. 



Specific electrical resistance = 7*56 x 10 -6 ohms. 



10 cms. between junctions. Time-period 20 min. 



Determination of temperature every minute. 



Set I. 





Set II. 



(Mean of 4 cycles. 



) 



(Mean of 3 cycles.) 



Excess Temperature 



Excess Temperature 



in degrees. 





in degrees. 



Time in 



A. 



B. 



A. 



B, 



mins. 

 

 1 











2412 



10-29 



23-67 



1013 



2 



17-60 



10-07 



1733 



1002 



3 



1266 



9-15 



12-62 



909 



4 



9-23 



7-80 



9-34 



7-91 



5 



688 



6-54 



695 



669 



6 



5-23 



5-40 



5-46 



5-60 



7 



401 



4-52 



4-27 



4-68 



8 



318 



3-76 



3-33 



391 



9 

 10 

 11 



2-43 



313 



2-60 



330 



2-46 



2-17 



2-54 



2-34 



12 



9-40 



202 



• 9-27 



2-26 



13 



1523 



2-95 



14-87 



307 



14 



1904 



4-33 



18-68 



4-39 



15 



21-48 



5-70 



2113 



5-78 



16 



23-26 



6-94 



22-78 



6-88 



17 



24-49 



7-88 



2389 



7-90 



18 



25-26 



8-66 



24-64 



8-70 



19 



25-76 



934 



2516 



9-36 



Mean Temp 26|° 



18^° 



28° 20£° 



Mean Temp. | , ( 

 Air. J li 



S° 



1H° 



Whence by calculation : — 





Setl. 



Set II. 



Conductivity 







(from 1st sine term). 



•2351 



•2338 



Emissivity : — 







From "a" term. 



•000253 



•000236 



„ 1st sine term. 



•000301 



•000286 



Set II. is the better of the two. 







