260 SIR DAVID BREWSTER ON THE 



1841, December 5. 



Apparent Time. 



ll h m a.m. R=25|° in zenith plane. 



1841, December 7. — Neutral line convex towards the sun. 



Apparent Time. Babinet. 



8 h 51 ra a.m. 15° 4' 



1841, December 11. — Barom. 294; therm. 41. 



Apparent Time. Arago. 



3 h 46 m R=28l in zenith, and in 20° above horizon. 18° 27' 



3 51 16 16 



Although the sky appeared free of clouds, yet, upon close examination, ex- 

 tremely faint and transparent clouds reflecting no light, but rather darker than 

 the sky, covered the whole heavens. 



1841, December 17. — Beautiful morning. 



Apparent Time. Babinet. 



9 h 7 m a m. R = 27|° in S.W. horizon. 



9 13 Neutral line concave to sun. 13° 10' 



10 30 R=27|-° in zenith plane; 25|°, 30° above N.E. horizon. 



1841, December 18. — Splendid sky; without a cloud. 



Apparent Time. Babinet. 



8 h 53"» a.m. 15° 55' 



Arago. 

 9 8 19° 52' 



At 9 h the maximum polarisation R=28° in zenith plane, and far beyond 90° 

 from the sun. 



Apparent Time. Arago. 



3 h 17 m pm. 19° 5' 



3 32 17 25 



Babinet. 

 3 22 R=28° in zenith ; 27i° in horizon. 17° 20' 



3 36 18 25 



1841, December 22. — Fine frosty day ; clear sky. 



Apparent Time. Babinet. 



9 h 23 m 14° 10' 



Aiago. 

 9 33 20° 10' 



R = 27|° in zenith plane ; 24-|-° in S.W. horizon, and 26£°, 10° above. 



1842, January 6. — Fine day. 



Apparent Time. Arago. 



2 h 34 m 19° 6' 



Babinet. 



2 38 16° 18' 



R=2i° in zenith plane ; 28^°, 30° above E. horizon. 



