354 Sir David Brewster on the Polarization 



1842, April 16. 



Apparent time. Arago. 



h m „ , 



5 54 ..- .. .. .. 17 25 



6 31 .. .. .. .. 22 22 



6 59 fR=27^° in zenith ;22|° in N., and 18£°) ^ 5Q 



\ in S. horizon . . . . J 



7 21 18 55 



7 35 R=18|°atnoon .. .. 45 



7 46 .. .. .. .. 23 50 



Babinet. 



5 58 R=23|° in zenith, much less in horizon. 25 40 



6 33 / R=23° in zenith ; 21° in W., and 18±° 1 19 g " 



\ in E. horizon . . . . J 



6 57 . . . . . . . . 20 3 



7 23 R= 29^° in zenith, and 24|° in hothhor. 17 45 

 7 37 R=31° in zenith, and 29|° in horizon. 17 35 



1842, April 17.— Slight haze. 



3 30 Brewster's neutral point distinctly seen, R = 19|° in zenith, 

 and 12° in S. horizon. Arago. 



5 34 R= 171° in zenith, 22|° in hor. ; clear sky. 20 10 



Babinet. 



6 3 Babinet's neutral point just risen 19 30 



7 35 R=28^ in zenith plane. 



1842, April 18.— Barom. 30 in, 



7 14 Pol. moon =271°, 29^° in zenith. 18 45 



Arago. 



7 23 Pol. moon =28|° i 30f° in zenith. 17 45 



1842, April 19. 



7 17 16 35 



Babinet. 



7 20 Pol. moon 14^° and a maximum . . 18 15 



7 37 „ 22 J°, and maximum 26^° 19 10 



1842, April 20.— See Phil. Mag. vol. xxx. pp. 125, 168. 

 1842, April 21.— See Phil. Mag. vol. xxx. p. 173. 



11 30 R=23|°, maximum at 90° from sun. 



1 10 R=25|°, maximum at 90° from sun. 



Arago. 



7 20 1755 



7 48 A fog came on . . . . 14 24 



Babinet. 



7 22 .. .. .. .. 20 15 



1842, April 22.— FiDe day. 



1 1 10 a.m. R= 17|°; maximum polarization in zenith 90° from sun. 



Brewster. 



2 „ R=27 <? at 90° from sun in zenith plane. 12 10 



3 „ R= 29° at 88° from sun in zenith plane. 11 10 



4 10 „ R=29i° at 90° from sun. 



Arago. 



6 55 „ 20 25 



Babinet. 



6 58 „ Thin clouds. . . . . 22 15 



