64 



Captain Lefroy^s Second Report on 

 Table II. {continued). 



(a) Commeuciug on the 19th. (4) Down on the 11th. (c) Down to the 10th. 



In these enumerations^ doubtful entries are not included unless 

 supported by an observation elsewhere in the same region. I 

 have added the number of observations made by a most indefa- 

 tigable observer (Dr. Franklin B. Hough) at Somerville, near 

 Ogdensburg, on the St, Lawrence, both as properly belonging 

 to the Canadian chain of stations, and to show that even in low 

 latitudes a single observer, by gTeat attention, may make a sur- 

 prising advance on the number of instances of aurora, which 

 attract the attention of those who are less zealous or less favour- 

 ably situated. The stations may be arranged in three groups ; 

 the first comprising all those marked (a), which are from 500 

 to 1000 geographical miles distant from the magnetic pole ; the 

 second, those marked {b), which are from 1200 to 1500 raUes 

 distant; and the third, those marked (c), including the great 

 majority of stations in the United States, which arc from 1600 

 to 2000 miles distant, from the same point. Lake Athabasca, 

 contrary perhaps to first impressions, is the nearest permanent 

 station to this assumed centre of influence. Fort Confidence, 

 which is not a pei-manent station, is of course nearer ; but Fort 

 Simpson and the other posts on McKenzie's River, notwith- 

 standing then- northerly position, are somewhat more distant. 



