NO. II USE OF THE PYKANOMETER ABBOT AND ALDRICH 



4. Current 0.802 amp. Extra resistance 560 ohms. Deflections 

 18 to 22 cm. 



Proportion of final. .820! .956 .98/1 .995; .9971 .999 



i.ooo i.ooo i.ooo 



.999 



B. With Swedish galvanometer.* Resistance 15 ohms. 



I. Current 0.300. No extra resistance. Deflections 2.8 to 3.0 cm. 



Time in seconds.. . . 4 10 

 Proportion of final. I .915 .965 



15 

 .984 



20 

 • 994 



25 30. I 40 50 I 60 /3 



.994 .997|i.ooo|i.ooo|i.ooo j.ooo 



I I I I 



2. Current 0.385. No extra resistance. Deflections 4.6 to 5.0 cm. 



Proportion of final. I .915 .965 



.985 



.995I .996: .998 1. 000] 1. 000 



I.ooo I.ooo 



From these experiments we see that the deflection attained after 

 the first swing, or after any specified interval, is closely proportional 

 to the final deflection whatever the strength of the heating employed. 

 The final deflection is approximately attained in 20 seconds. 



On the proportion borne by the deflection observed after fixed 

 intervals to the final defiection, due to emission of nocturnal radiation. 

 Glass hemisphere off. 



A. German galvanometer. No extra resistance. 



Time in seconds 



Deflection in cm 



Proportion of final 



Previous result with current. 



Final 

 11.89 

 1 .000 

 I.ooo 



B. Swedish galvanometer.* No extra resistance. 



Time in seconds 



Deflection in cm 



Proportion of final 



Previous result with current.. 



Final 

 2.09 

 I.ooo 

 1 .000 



We here read the first swing, which occurred in approximately 4 seconds. 



