The Aueoea Borealis. 



Ixxv 



167- Motions with reference to the Moon's Hour-Angle. — These, as obtained from the means of all the luna- 

 tions in the years 1844 and 1845, and as deduced from winter lunations for 1845 only, are shewn in 

 Plate VII. The resulting figures, especially that for the winter lunations of 1845, bear some resemblance to 

 the diurnal motion for the month of December. 



The Aurora Borealis. 



168. The results for the aurora borealis are placed between the magnetical and meteorological discussions, 

 because the appearances of this meteor are distinctly connected with magnetic disturbances ; the frequency of 

 the one and the magnitude of the other, it will be seen, are governed by the same laws. 



169. The following Table contains a list of all the auroras seen at Makerstoun, between January 1843 and 

 June 1849. A very careful outlook for aurorse was kept throughout the whole period, but especially during 

 the first five years ; an outlook warned by magnetic disturbance in circumstances unfavourable to the visibility 

 of the meteor, and assisted by a practical acquaintance with the faintest auroral indications. In several cases, 

 the auroral appearances were very faint; these are entered in the Table as "Traces," and, in others, there was 

 doubt whether the appearance was truly auroral ; these are indicated by " Trace ?" It should be noted that, 

 with the exception of the years 1844 and 1845, aurorse were seldom looked for after midnight. 



Table 69. — List of Aurorse Boreales seen at Makerstoun in the years 1843-9. 



Date, 



Gbttingen 



Mean Time. 



Moon's 

 Age. 



Sky 

 Clouded. 



Species 

 of Clouds. 



Character 

 of Magnetic 

 Disturbance. 



General Remarks. 



Page 

 of Refer- 

 ence. 



1843. 



d. h.— h. 



d. 











(1843.) 



Jan. 28 8 



28 



00 





Slight 



Traces. (Seen at Christiania.) 



93 



Feb. 24 10—13 



25 



9-7 



Scud 



Moderate 



Traces. (Seen at Christiania and in United States.) 



201 



Mar. 6 14 



5 



20 



Cum.-scu(i 



Moderate 



Seen through clouds. 



203 



7 8 



6 



0-0 





Moderate 



Arch 10° altitude. 



54 



12 9—13 



11 



20 



Scud 



Considerable 



Distinct. 



54 



29 9—12 



28 



00 





Moderate 



Segment of circle 15° alt. lO^**, equatorial beam. 



111,61 



Apr. 5 9—14 



6 



00 





Considerable 



Bright arches and streamers. 



61 



6 14—16 



7 



00 





Considerable 



li*" ; arch 10° broad, 15° altitude. Corruscations. 



205 



Sept. 18 10—12 



24 



2-5 



Cirro-str. 



Moderate 



Bright. 14'' 35" ; 12° altitude. 



213 



19 10 



25 



9-8 



Cirrous 



Moderate 



ll*" ; band 10° altitude ; seen through clouds. 



69 



20 14—15 



26 



1-6 



Scud 





Traces. (Seen at Christiania.) 



69 



Oct. 15 10 



21 









Auroral arch 15° altitude. Streamers. 



173 



16 10 



22 



9-8 



Cirrous 



Slight 



Traces througb clouds. 



175 



26 8—10 



3 



0-5 



Loose cum. 



Moderate 



9^ 50-" ; arch 8° altitude. 



177 



Nov. 2 10 



10 



0-2 





Slight 



Traces. 



70 



13 8—10 



21 



9-8 



"Various 



SHght 



Distinct. [places. 



183 



14 10 



22 



8-0 



Cir.-strati 



Slight 



Traces. 12*^ ; magnets slightly disturbed at other 



183 



Dec. 11 10 



19 



50 



So.; cir.-str. 



Moderate 



Distinct. 



71 



12 8 



20 



100 



Scud 



Moderate 



Traces; through clouds. (Appearances at Parma.) 



191 



27 6 



6 



0-8 



Scud 



Slight 



Traces. 



72 



1844. 













(1844.) 



Jan. 5 10 



15 



90 



Scud 



Moderate 



Traces. 



174 



10 10—11 



20 



20 



Cirri 



IModerate 



Traces. 



175 



Feb. 7 9 



19 



0-5 



Loose scud 



Moderate 



Faint. 



186 



11 13—14 



23 



5-5 



Cirri 



SHght 



Traces. (Suspected at New Haven, Connecticut.) 



187 



22 8 



4 



50 



Cirri 



Slight 



Traces. 



158 



Mar. 2 9 



13 



10 



Scud; cir. 



Moderate 



Trace. (Bright moonlight.) 



158 



7 8—10 



18 



10 



Cir.-str. 



Moderate 



Rather bright. Arch and streamers. 



158 



9 13 



20 



20 



Sc. ; cirri 



Moderate 



Rather bright. 



158 



12 11 



23 



01 



Cirri 



Slight 



Faint. 



158 



29 11—16 



12 



0-1 



Cirri 



Moderate 



Bright. Arches and streamers. 



158 



Apr. 5 12—14 



19 



0-2 



Cir.-str. 



Moderate 



Streamers, arch and band. 



158 



10 13 



23 



0-9 



Cir.-str. 



Slight 



Traces. 



209 



17 11—12 







5-0 



Cirri 



Considerable 



Faint streamers and homogeneous light. 



158 



May 8 11—12 



21 



1-2 



Cirri 



Moderate 



Faint. 



158 



MAG. AND MET. DBS. 1845 AND 1846. 



