ON THE PERIODICITY OF THE AURORA BOREALIS. 



197 



GENERAL CATALOGUE OF AURORAS. Continued. 



Year 

 1643 



1644 

 1645 

 1646 

 1650 

 1654 

 1G55 

 1657 

 1660 

 1661 

 1662 

 1663 

 1664 

 1665 

 1666 

 1671 

 167-2 

 1676 

 1677 

 1680 

 1682 

 1683 

 1684 

 1685 

 1686 

 1 687 

 1690 

 1692 

 1693 

 1694 

 1695 

 1696 

 1 697 

 1698 

 1699 

 1701 

 1702 

 1703 

 1704 

 1706 

 1707 

 1708 

 1709 

 1710 

 1711 

 1714 

 1710 

 1717 



Apr. May June July Aug. | Sept 



6? 



Oct. 



Die. 



1? 



2 

 1 



Total 



1 



1 

 1 

 1 



1 

 1 



1 



2 

 1 

 2 



1 

 1 

 1 

 2 

 1 

 1 

 1 

 2 

 2 



1 



2 



2 



2 



1 



4 



1 



3 



3 



2 



2 



4 



4 



1 



9 

 40 



1 



1 



6 



1 



1 

 16 



4 



3 



3 



1 



1 

 13 

 17 



