ON THE PERIODICITY OF THE AURORA BOREALIS. 



183 



XIX. AURORAS OBSERVED AT PLYMOUTH, ENGLAND, ARRANGED BY YEARS AND MONTHS. 



Year 



1728 



1729 

 1730 

 1731 

 1732 

 1733 

 1734 

 1735 

 1736 

 1737 

 1738 

 1739 

 1740 

 1741 

 1742 

 1743 

 1744 

 1745 

 l"74G 

 1747 

 1748 



Total 



1 



2 



3 

 3 

 2 

 5 

 1 



23 



Apr. 



May 



12 



June 



July 



"~3~ 



Aug. 



Sept. 



Oct. 



Nov. 



10 



15 



13 



Total 



13 

 8 



7 

 6 

 2 

 9 

 3 

 2 

 11 

 9 

 G 

 7 

 4 

 7 

 6 

 4 

 2 

 2 

 4 

 5 

 3 



120 



XX. AURORAS OBSERVED AT MAKERSTOUN, SCOTLAND, ARRANGED BY YEARS AND MONTHS. 



Total 



22 



26 



4 

 5 

 11 

 1 

 1 

 4 

 2 



~28 



Apr. 



2 

 3 

 4 

 2 



1 

 2 

 2 



16 



May 



June 







July 



Aug. 



16 



Oct. 



3 

 4 

 4 

 4 

 5 

 7 

 2 



29 



3 

 6 

 3 

 1 

 5 

 5 



Total 



23 



XXI. AURORAS OBSERVED AT DUNSE, N. BRITAIN, ARRANGED BY YEARS AND MONTHS. 



1838 

 1839 

 1840 

 1841 

 1842 

 1843 

 1844 

 1845 

 1846 

 1847 



Total 



Apr. 



3 



4 

 4 

 4 



1 



1 



3 i 



18 I 18 



JUDe 



July 



Aug. 



1 



2 

 1 



IT 



Sept. 



4 

 11 

 T 

 3 

 3 



1 

 2 



7 

 5 



Oct. 



1 



7 

 6 

 3 



3 

 3 

 1 

 4 

 6 



~34~ 



2 

 2 

 6 

 7 

 1 



4 

 1 

 1 

 6 



~3~cT 



Dec. 



23 



Total 



27 

 38 

 43 

 42 

 9 

 10 

 13 

 10 

 16 

 30 



238 



