214 



SIR DAVID BREWSTER 



1841, 



June 3. 





Mean Time 





6h 27'" p.* 





6 36 „ 





6 43 „ 





7 8 „ 





7 35 „ 





8 4 „ 





8 33 „ 



Height of Neutral Point above 

 the Antisolar Point. 



Neutral Point not risen. 



very near the horizon. 



above and close to the horizon. 



Sun sets. 



18° 20' 



20 30 



21 43 



1841, June 10, 2*".— Barom. 297. Singularly fine sky all day; wind east. When 

 the neutral line or point of the polarimeter happened to be above an illuminated 

 wall, the effect was to vary the place of the neutral, as if the polarisation of the 

 sky were diminished. At Z^ 47™, when the sky was everywhere pure and free 

 of clouds, the neutral line of the polarimeter was curved above the land horizon. 

 At 6h 32™ its curvature was greater above the sea horizon, the deviation increasing 

 towards the horizon. 



Height of Neutral Point above 

 the Antisolar Point. 



Mean Time 





In Zenith. 



jiariHui'iuu. 

 In Horizoi 



6^ 35°» P.M 



Neutral 



point in horizon. 





7 13 ., 





• • • 



... 



7 30 „ 





28^ 



28^ 



7 42 „ 





. . . 





8 5 „ 





29i 



28^ 



8 18 „ 





... 



29^ 



8 36 „ 



Sun set. 



... 





8 52 



29^ 



1841, July 17.— Barom. 2960, therm. 55^^ 

 sky, with clouds here and there. 



Mean Time 



7" 



35"° 



P.M 



8 







S) 



8 



18 



)> 



8 



30 



)) 



8 



47 



J> 



9 



2 



» 



9 



12 



») 



9 



22 



» 



Sun sets. 



30 



18° 



20' 



18 



56 



21 







19 



15 



18 



56 



19 



25 



19 



29 



uth-west. 



A China-ink 



Height of Neutral Point above 



the Antisolar Point. 



19° 



0' 



17 



48 



17 



25 



17 



45 



17 



19 



16 



15 



17 



26 



19 



7 



1841, August 31. — Rain till I'' p.m., when it cleared up. Barom. 297. 



Mean Time. 



R:=Maximum 



Polarisation. 



Height of Neutral Point above 



In Zenith. 



In Horizon. 



the Antisolar Point. 



5h 44m p M, 



27*= 



isr 



17° 22' 



6 „ 



281 



22i 



19 55 



6 20 „ 



... 



... 



19 59 



6 38 „ 



• . * 



. * • 



20 3 



