ON THE PERIODICITY OF THE AURORA BOREALIS. 



195 



GENERAL CATALOGUE OF AURORAS ARRANGED BY YEARS AND MONTHS. 



Tear Jan. Feb. 



BEKOR 



1309 



1309 



1325 



1351 



1352 



1353 



1354 



1361 



1375 



1399 



1437 



1146 



14(51 



1465 



1499 



1514 



1518 



1520 



1.3-27 



1529 



1.331? 



153U? 



1.334 



1535 



1536 



1537 



1538? 



1541 



1543 



1545 



1.346 



1.317 



1548 



13 Li 



1.351 



13.34 



1.3.35 



1.3.3 6 



1557 



1560 



15r,l 



1562 



1563 



1564 



1565 



1567 



1563 



10 



Mar. Apr. 



l 



2 



May 



July 



Aug. Sept. 



Nov. i Dec. 



13 



168 



2 

 2 

 3 

 2 

 1 

 1 

 1 

 1 

 1 

 1 

 1 

 1 

 1 

 2 

 1 

 2 

 1 

 2 

 3 

 2 

 2 

 2 

 2 

 2 

 4 

 1 

 2 

 5 

 1 

 2 

 3 



* The total number of the year sometimes exceeds the sum of those placed in the monthly columns because auroras were observed 

 when the month was not mentioned, but the year only. 



