512 MAJ0E-GI2sEEAL SAEIXE OX THE EESELTS OF HOUELT OBSERYATIOXS 
aurora are registered, and which much exceeds, I believe, any previous record of the 
kind. It was the custom of Captain Maguiee and his officers to make a distinguishing 
mark opposite to the entry of every hourly obseiwation of the declinometer when aurora 
was visible ; and in the Tables received at 'SYoolvich, the observations so distinguished 
are written in red ink, and those when no aurora was visible, in black ink. In the 
months of December, January and February, in which months there was scarcely any 
daylight, and the sky was generally freest from clouds, we find, in the ffi’st year, the 
whole number of hourly observations in the tliree months to have been 1786; the 
number at which aurora was seen, 464; and the number at which it was either not 
present or obscured by clouds, 1322 ; and in the same three months of the second year, 
the numbers were respectively 1837, 615 and 1222. Thus, in the six months, there 
were 1079 hours when aurora was seen contemporaneously with the declinometer 
observation, and 2544 hours at which it was either not present or not tisible ; in other 
words, aurora was actually seen contemporaneously with little less than one-third the 
number of hourly observations in the sis months. The hours when aui’ora was most 
common were from 7 p.m. to 7 a.m. ; and if we examine on how many days in the above- 
named sis months the aurora was seen, and on how many days it was not seen, we find 
that it was seen between 7 p.m. and 7 a.m. on 131 days, and that it was not seen (during 
the whole twenty-four hours) on 22 days ; or, as it may be otherwise stated, during the 
months of December, January and February, in two successive years, the aurora was 
actually seen sis days out of every seven. 
When the 1079 observations of the aurora are distributed into the difierent hours of 
their occurrence, we find them to have been as follows : — 
Table VI. 
Showing the number of times that the Aurora is recorded to have been seen at the 
several observation-hours in the months of December, Januaiy, and Februaiy 
1852-1853, and in the same months in the following year. 
Hours of local 
civil time. 
Number of 
auroras 
observed. 
Hours of local 
civil time. 
Number of 
auroras 
observed. 
Hours of local 
civil time. 
Number of 
auroras 
observed. 
Hours of local 
civil time. 
Number of 
auroras 
observed. 
6 A.M. 
66 
Noon. 
0 
6 P.M. 
30 
Midnight. 
85 
7 A.M. 
54 
1 P.M. 
0 
7 P.M. 
56 
1 A.M. 
103 
8 A.M. 
28 
2 P.M. 
0 
8 P.M. 
56 
2 A.M. 
98 
9 A.M. 
10 
3 P.M. 
0 
9 P.M. 
60 
3 A.M. 
95 
10 A.M. 
2 
4 P.M. 
5 
10 P.M. 
77 
4 A.M. 
80 
11 A.M. 
0 
5 P.M. 
15 
1 1 P.M. 
88 
5 A.M. 
71 
We perceive by this Table, that there is not a single instance recorded of the aui'ora 
having been seen between II a.m. and 3 p.m., both hours included ; and as there is httle 
or no daylight at these hours during the months in question, the general absence of 
aurora (and not merely its inmsihilUy) in this part of the twenty-four hours may fairly 
be inferred. The most frequent hour of its appeai’ance is I a.m. ; and the great degree 
