230 



SIR DAVID BREWSTER 



1842, April 15 and 17. 



Apparent Time. 



3h Qm Neutral point below the sun distinctly seen 

 3 30 



1842, April 20. — Barom. 30-02. Very fine day ; wind west. 



Apparent Time. Distance of Neutral Point from Sun. 



12^ 10m no 20' 



12 37 10 40 



2 21 12 



3 45 12 35 



The maximum polarisation was very great. 



1842, April 25. — Thin hazy clouds before the sun. 



Apparent Time. 



l*" 11™. Sun's alt. 45i°. Alt. neutral point below sun 34°. Distance below 

 sun lli°. " 



1842, April 26. — Barom. 3008. Not a cloud in the sky from morning till 

 night. 



Apparent Time, 

 llh im 



11 46 



3 30 



3 35 



4 10 



Distance of Neutral Point from Sun. 

 12° 15' 



12 30 



14 35 



15 5 



17 45 



1842, April 27.— Barom. 3004. Singularly fine sky. 



Apparent Time. Distance of Neutral Point from Sun. 



10'' 45m 12° 5' 



12 12 A fog from the sea has just come on, and has driven the neutral point 



beneath the horizon, the bands being negative all the way to the horizon. 



1 20 The fog has diminished. The neutral point is now seen near the horizon, 



playing up and down from 4° to 6° above the horizon, as the fog 



becomes denser or rarer ! 



1842, April 28.— Barom. 30. 



Apparent Time. 



llh 24™ 

 1842, April 29. 



Apparent Time, 

 llh 4m 



1842, May 3. — China-ink sky; wind east. 



Apparent Time, 

 ll'' 29m 

 12 15 



Fine sky ; wind east. 



Distance of Neutral Point from San. 



10° 55' 



Distance of Neutral Point from Sun. 



11° 20' 



Distance of Neutral Point from Sun. 



10° 15' 



9 25 



1842, May 16. — Barom, 303. Thick haze; sun faintly seen. 



Apparent Time. 



Qh 49m ^ j£ Neutral point below the horizon. The sun now quite hid, and no 



bands seen below him. A great glare of light, and a sort of quaqua- 



versus polarisation. 



N.B. — When tlie neutral point is out of the plane passing through the sun, 



the zenith, and the observer, it arises in certain cases from there being a 



greater haze on one side of the plane than on the other. 



