164 M. J. A. Angstrom on the Conducting -Power of 



In all the experiments one thermometer was read by M. Thalen, 

 and the other by myself. 



Copper Bar, Thermometers No. II. and No. III. 



No. 



Period. 



k 

 cS' 



Temp. 



Remarks. 



1 

 2 

 3 

 4 

 5 

 6 

 7 



24 

 24 

 24 

 16 

 24 

 24 

 24 



62-19 

 63-61 

 63-64 

 65-77 

 6595 

 6607 

 66-45 



71°-5 



550 

 56-6 

 410 

 42-4 

 32-2 

 28-8 



Single series. Heating by means of a gas-flame. 



„ „ vapour of water. 

 Double series. „ „ „ 



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»> » >i »» 



Iron Bar. 



1 

 2 

 3 



32 

 32 

 32 



10-487 

 10-429 

 10-279 



43-4 

 43-7 

 18-9 



Single series. Thermometers Nos. II. and III. 

 Double series. Thermometers A and B. 



If the value for the copper bar of 



A 



be calculated by the method of the least squares (it being assumed 

 that all the observations are of equal authority), the following 

 equation will be obtained, 



4 =69-77(1-0-001519 0. 



k 

 If the observed values of -^ be calculated according to this 



formula, they will be found as follows : — 







Calculated, 



Difference be- 



No. 



Temperature, 



k 



tween observation 







ci' 



and calculation. 



1 



715 



62-192 



-0002 



2 



550 



63-941 



-0-331 



3 



56-6 



63-771 



-0131 



4 



41-0 



65-424 



+0 346 



5 



42-4 



65-276 



+0-674 



6 



32-2 



66-357 



-0-287 



7 



28-8 



66-717 



-0-267 



2e 2 = 0-8544 



The probable error in the value of the constant 69*77, or the 

 conducting-power at 0°, is thence obtained, 



= +01093. 



