458 Sir David Brewster on the Polarization 



1843, April 29.— See Phil. Mag. vol. xxx. p. 165. 



1843, April 30. — Barora. 30*07 in. Morning, and rising. 

 Not a cloud. 



Apparent time. 



h m Arago. 



1 R=26a° max. pol. in zenith, 22i° in hor. , 



4 15 R=26i 



5 43 Secondary neutral point forming. 



6 4 .... .. .. 11 20 



6 52 R=29° max. pol. in zen., 22|° in hor. 19 20 



7 33 R= 29i° max. pol. in zenith, 22£° in hor. 1 9 35 

 7 58 .. .. .. .. 19 3 



A brown haze rising up upon the blue sky. See Phil. Mag. 

 vol. xxx. p. 169. 



1843, May 2.— Barom. 30*07 in. Wind east; no sun. 



Babinet's neutral point near zenith, and polarized bands 

 scarcely seen, excepting at 90° from sun. 



1843, May 3.— See Phil. Mag. vol. xxx. p. 165. 



6 49 18 26 



Babinet. 



6 53 R=30° max. pol. in zenith, 27° in hor. 14 20 

 Very clear in zenith, with a whitish sky. 



1843, May 6. — Wind east ; uniform China-ink clouds over 

 the sky, through which the sun shone brightly, but ill -defined. 



4 h 43 m . — Polarized bands distinct over the face of the sun and 

 above him, but exceedingly feeble opposite the sun. 



1843, May 11.— Barom. 30 in. Fine day. 



Arago. 



2 30 R=20|° max. pol. in zenith plane. 



6 Neutral point not up . . . . 14 34 



6 12 R=23£° maximum polarization in zenith. 18 15 



Whitish-blue sky. White clouds in horizon. 



1843, June 13— Barom. 30 in. Wind east. 



6 56 19 15 



9 10 . . . . . . . . 20 25 



Babinet. 



7 R=27|°max. polarization in zenith plane. 25 10 

 9 13 R=29i° in zenith, horizon clear. 15 30 



1843, June 14. — Barom. 30*07 in. Splendid day ; wind east. 



6 12 R =29^° max. pol. in zenith, 2H° in hor. 13 30 



7 59 R=29i° „ „ 22^° in hor. 15 30 



Arago. 



» f R = 29|° max. pol. in zenith, 22^° in ho- \ j ] 5 



\ rizon. Neutral point in horizon. \ 

 7 56 . . . . . . ., 18 20 



