378 Magnetic Influence of Solar Light. 



TABLE V. 



Shewing Duration of Oscillations of Testing Needle, with Cylinder E in 

 front, before and after exposure. 



Medium Very Dark Red Glass. 



Oh 



d. 



X 



W 



Hours of 

 Expos. 



o 



(4-1 



o . 



. d 



Temp. 



'o 



Duration of 

 Oscillations. 





| No. of E: 







jii a 







| No. of Os 









Date of 



From 



A. M. 



To 



P. M. 



Lengt 

 Cyli 



Diam. 

 Cyli 



Before 

 Expos. 



After 

 Expos. 



Before 

 Expos. 



After 

 Expos. 



Remarks. 



1 



2 

 3 



Feb. 

 28th 



11 



3 



In. 



2 



In. 

 0-05 



72° 



91° 



10 

 10 

 10 



97 

 96 

 97 



97 

 97 

 97 



Wind high 

 at first. Expo- 

 sure, repeated 

 after wind lul- 

 led. 



4 

















10 



97 



97 





5 

















10 



97 



97 

















i 



Sums ... 



50 



484 



485 















Means ... 



10 



96-8 



97 



h 



From the preceding experiments it may with safety be 

 concluded, that no magnetic influence whatever is exerted 

 by light, transmitted through coloured glass media; and as 

 in former instances, it may be inferred that the results 

 obtained by Mrs. Somerville were in reality due to the 

 action of some unrecognised cause, capable of producing 

 magnetic phenomena. Even supposing, in the present in- 

 stance, decisive indications of such phenomena had been 

 obtained, it would still have been fairly a question whether 

 they were due to the decomposed light, for it must be 

 recollected that metallic oxides are the chief materials em- 

 ployed in imparting colours to glass and some of these 



