6 



W] 



6 



46 



7 



40 



8 



4 



7 



43 



8 



10 



POLARISATION OF THE ATMOSPHERE. 271 



1842, August 6.— Barom. 29*6; rain at 5 h p.m. 



Apparent Time. 



7 h 50 m R=28|° max. in zenith plane to 24|-° in horizon. 



7 56 Altitude above horizon of Arago's neutral point. 19° 10' 



Clouds around the blue space. 



1842, August 11.— Barom. 2962; rain in morning. 



Apparent Time. 



5 h 30 m R = 23|° in zenith plane, and 20^° in S. horizon. 



5 51 + Bands opposite sun almost gone at 1|° above hor. 



Arago. 



6° 40' 



14 35 



20 35 



Altitude of the two neutral points above the horizon.^ 22 20 



Babinet. 



18° 25' 

 R= 29° in zenith. [ 12 



1842, August 17.— See "Edinburgh Transactions," vol. xxiii. p. 231. 

 1842, August 22.— Warm ; fine day. 



Apparent Time. 



oh oom / R=24|° maximum polarisation in zenith plane to 



\ 19|° in horizon. Arago. 



5 52 18° 36 



6 37 R= 27 J° in zenith plane. 21 16 



7 26 R = 28i in zenith plane. 19 56 

 7 49 22 8 



Babinet. 

 7 52 13° 8' 



1842, August 28. — See "Edinburgh Transactions," vol. xxiii. p. 231. 



1842, September 9. — Barom. 291, after rain. 



Apparent Time. 



5 h 53 m R = 26J C maximum polarisation in zenith, to 25 J° in horizon. 



Arago. 

 6 38 18° 57' 



1842, September 13.— Barom. 2993. Fine day. 



Apparent Time. 



4 h 39 m R = 28° maximum polarisation in zenith plane. 



Arago. 

 4 50 ( horizon, to 24^° in horizon. In S. horizon, alt. |> 15° 35' 



R = 27-2° maximum polarisation in 30° alt. N.W. 

 horizon, to 24^° in horizon. 

 30° 261° to 22 \° in horizon. 



18 35 

 R = 29i-° maximum polarisation. Pol. of moon 19J°. 20 17 



20 

 16 24 

 Babinet. 



R=29° maximum polarisation in zenith. 14° 25' 



15 40 



R = 29^° maximum polarisation in zenith. 16 6 



19 8 

 VOL. XXIV. PART II. 4 E 



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