264 



Magnetic Influence of Solar Light, 



TABLE XVII. 



Shewing Duration of Oscillations of Testing Needle, with soft, iron wires in 

 front, before and aftet exposure. 



Diam. of 

 Wire. 



Hts. of 

 Wire. 



Ox. or Pol. 



No. ofOscill. 



| Dur, of Os- 

 cill. before 

 Expos. 



Dur. of Os- 

 | cill. after 

 | Expos. 



Remarks. 



In. 



In. 













0.031 



1 



Ox. 



10 



67 



68 







2 



Pol. 



10 



74 



73 







3 



Ox. 



10 



78 



79 







4 



Pol. 



10 



86 



86 







5 



|Ox. 



10 



86 



87 









Hours of 



Temp. 



d> 



X 





Expos. 







W 



5.* 







<U TO 





o 









IS. 









A. M. 



P.M. 







o 











Feb 



From. 



To. 







1 



5th. 







59° 



82° 



2 













3 













4 



5 













Whence it appears that iron wires are not more adapt- 

 ed for exhibiting the magnetic action of undecomposed 

 light than steel ones, and the general conclusion to which 

 all the experiments detailed clearly point, is, that such 

 action has no real existence, and that the effects attributed 

 to it must have been due to some interfering cause capable 

 of producing changes of magnetic condition, but unrecog- 

 nised, and therefore not provided against by the observers. 

 Having been unable to procure even the briefest statement 

 of the details of M. Baumgartner's experiments, I cannot 

 attempt to point out any sources of fallacy that may have 

 vitiated their results, but of the existence of these I can 

 entertain but little, if any, doubt, after the observations just 

 described, which shew in the clearest manner, that when 

 proper precaution were observed, the magnetic condition 

 of the steel and iron wires, under experiment, continued iden- 

 tically the same before and after exposure to the sun's light. 



Camp near Saharanpore, 

 15 th February, 1842. 



(To be continued.) 



