456 Sir David Brewster on the Polarization 



1843, January 30.— Barom, 29'50 in. Windy. 



Apparent time. Arago. 



h ni o , 



12 18 Neut. point below hor. R=21° max. clear. 15 40 



1 ; * 1 Neutral point below horizon, R=24t?° 1 -iq 9c 



'j in zenith to 14i° in horizon. \ 



2 28 .. .. .. .. 11 29 



3 52 R=28i° max. pol. in zen., to 2H° in hor. 16 29 



4 2 . . . . . . . . 18 32 



Babinet. 



3 55 . . . . . . . . 19 



3 10 R= 271° max. pol. in zen., to 21 1° in hor. 18 25 



1843, February 15. — Very cold day; clear only in north. 



Arago. 



2 57 .. .. .. .. 16 5 



1843, February 16. — Barom. 29*18 in., rising. Fine sky. 



Babinet. 



11 56 R=25° max. polarization, 20° in horizon. 



12 57 9 40 



Brewster. 



12 57 11 55 



Arago. 



3 28 R= 29i° max. pol. in zenith, 24^° in hor. 12 52 



4 3 R=29|° max. pol. in zenith, 26i° in hor. 18 40 



5 R=30 5 „ „ „ 17 52 



4 7 . . . • • . . . 14 52 



5 4 .. 17 26 



1843, February 17.— Barom. 29-6 in. Sky not clear in N. 

 horizon. 



3 6.. .. .. .. 11 28 



3 30 14 14 



1843, March 4.— Barom. 30-08 in. 



3 35 R= 1 4i° max. polarization in zenith plane. 1 6 45 



3 46 .. " .. .. .. 17 30 



o pa \ Secondary neutral point 50' high. Hazy ) •, « r * 



\ in horizon ... . . j 



4 6.. .. ... .. 20 30 



1843, March 7. 



4 40 R=24|° maximum polarization in zenith. 17 

 1843, March 8.— Barom. 30-13 in. Wind east ; hazy. 



4 14 R=24§° maximum polarization .. 17 47 



1843, March 12.— Barom. 29*34 in., after rain. 



4 2 R=25| max. pol. Pol. of moon 7°. 13 15 

 1843, March 25.— See Phil. Mag. vol. xxx. pp. 126, 165. 



1843, March 28.— Barom. 29*84 in. Wind east; dry. 



6 2 .. .. .. .. 16 45 



