[ 455 ] 



LVIII. Additional Observations on the Polarization of the Atmo- 

 sphere, made at St. Andrews in 1841, 1842, 1843, 1844, and 

 1845. By Sir David Brewster, K.H., D.C.L., F.R.S., #c. 



[Concluded from p. 360.] 



1843, January 4. — Fine day. 



Apparent time. Arago. 



a m o 



11 32 R = 27i° max. polarization in zenith. 14 41 



11 43 .. .. .. .. 14 30 



Babinet. 



1135 R=23±°tol8°. Haze coming on. 15 47 



1 51 Altitude of Arago's neutral point above 

 hor. 4° 30'. R=24i°tol8i°. Haze to 

 east and south. 



1843, January 5. — At Bankeilour M'Gill; clear and cold. 



Arago. 



11 27 JR^frir maximum polarization 18£° in"! -14 a* 

 J horizon. Neutral line convex to sun. J 



1843, January 10. — Barom. 28-5 in. Very cold. 



3 R=29° max. polarization in zenith plane. 14 25 



1843, January 11.— Barom. 2872 in. Finely. 



12 S'S J R = 26i° maximum polarization. Nebu- ) i c i c 

 ( losity in zenith . . . . \ 



1 47 R=29^° maximum polarization in zenith. 



Clear sky. 



2 55 R=28° max. pol. Slight nebulosity. 19 50 



3 10 Polarization of moon 15°. 



1843, January 21. — A misty day. 



2 46 R= 19a° max. pol. in zenith, 30° at 14° alt.16 40 



3 18 Misty .. .. .. 10 6 



The mist increased, and the maximum polarization everywhere 

 reduced to 14J°, and the two neutral points descended to the 

 horizon several degrees. 



1843, January 28. — Barom. 29*45 in. Very windy. 



12 28 



12 47 



1 57 



3 51 



Neutral point below horizon 

 ?) » 

 >i » 



Misty 



14 10 

 14 

 11 5 

 22 41! 



3 54 



12 28 



R=28£° max. pol. to 20£° in horizon. 

 R=26|° 18i 



Babinet. 



14 45 



