III. 



On the Periodicity of the Aurora Borealis. 



BY JOSEPH LOVERING, 



HOLLIS PROFE8SOK OF MATHEMATICS AND NATURAL FHILOSOrHY IN HARVARD COLLEGE. 



After my first catalogue, comprising nearly ten thousand independent auroras, 

 had been printed, other materials came into my hands which rendered necessary a 

 second catalogue, by which the aggregate of auroras was increased to nearly twelve 

 thousand. 1 Having succeeded in obtaining from Europe a copy of Frobes's book, 

 entitled Nova et antiqua Luminis atqae Aurorae Borealis Spectacula, I was able, in this 

 second catalogue, to give the places as well as the dates of most of the appearances 

 which Mairan had quoted from this work. Also, by the kindness of Professor Arge- 

 lander, I received a copy, in advance, of his Verzeichniss von Nordlichtem etc., Abdruck 

 aus den Abhandhngen der Finnischen Sorietiit etc., containing observations of the aurora 



o 



made at Abo, Wasa, and Helsingfors, between 1823 and 1837. Professor G. T. 

 Kingston has supplied me with the latest observations made at Toronto, and Professor 

 Charles Smallwood with others made at the Isle Jesus, in Canada. Mr. Charles A. 

 Schott has obtained for me, from the original records in possession of the Smithsonian 

 Institution, the dates of one hundred and eight auroras observed, between the years 

 1807 and 1859, by the late Professor Parker Cleaveland, at Brunswick, Maine. 

 General Lefroy, formerly Director of the Magnetic Observatory in Toronto, Canada, 

 has placed at my disposal his large accumulation of observations on the aurora, 

 collected in British America, particularly during the years 1848-1853. Also, Professor 

 Joseph Henry, Secretary of the Smithsonian Institution, has given me free access to 

 the unpublished records of meteorology, made, for a short period, in various parts 

 of the United States, under the auspices of this Institution, and in accordance with 

 the comprehensive plan of its Secretary. I have availed myself of the opportunity, 

 afforded by a recent visit to Holland, to search for the manuscript records of 

 meteorology kept by Musschenbroek at Utrecht and Leyden. In this attempt I 

 was heartily seconded by M. le Directeur de lTnstitut Royal Meteorologique des 



1 Those auroras marked by a star, in the second catalogue, are also contained in the first catalogue. 



vol. x. 39 



