146 On the Aurora Borealis of July 1, 1837. 
streamers were becoming shorter and less frequent. They were, 
however, for a long time, numerous about the N., and were visible — 
until overpowered by the superior light of the advancing sun. They » 
were distinctly observed as late as 3h. 30m., or about an hour after 
day break. 
Many observations on the position of the corona were made dur- ~ 
ing the night: those which are the most rele one are the fol- 
lowing, viz. 
2h. 31m. centre of corona, alt. 75° 25’ azim. S. 4° 27’ E. 
39 ee An ia i ic 3 30 
42 sf A WAO Leh bv OF 
| These positions correspond nearly to the direction of the dipping 
needle at this place, if we make due allowance for the perturbations 
which the Aurora may have occasionéd, and for the difficulty of de- 
termining with precision the central point. 
The horizontal needle was much disturbed. Between 10h. 44m. 
and 11h. it traversed 3° 4’. In general, the north end of the needle 
was carried to the east of its mean position at this place, which is 
now about N. 5°55’ W. After midnight, the range of variation did 
not exceed one degree. ‘The needle was not observed on the 2d or 
3d inst. 
From sunset to 2h. 30m. the wind was from N.W. and faint 
after that time, from’ N. N. W. and somewhat stronger. At 11h. 
40m. the dew point was 67°, therm. being at 72°. ‘The barometer 
rose during the night: at 2h. 30m. A.M. (2d inst.) it stood at 
29.76, at 6h. 29.80. Thermometer at 2h. 830m. 71°, at 6h. 69°. 
It is worthy of notice, that on this occasion there were two well 
marked and distinct seasons of greatest brilltancy or fits of maxi- — 
mum intensity, at an interval of about four hours. It will be found 
on examination of former accounts, that this is a common feature of 
Auroral exhibitions of unusual brilliancy, and that the first fit occurs 
within about an hour after the end of twilight. Future observations 
continued during the entire night, must determine the number of 
these seasons and the interval between them. ) 
The Aurora appeared on the night of Sunday, 2d inst. and was 
observed until 1h. 30m. of the 3d inst. It was not very conspicu- 
ous. At 9h. 30m. there appeared a low dim arch, with vertex about 
5° high, sending forth occasional streamers to an altitude not exceed- 
ing 30°, after which no special change was noticed. The day was 
clear and fine; therm. at 2 P. M. 78°. 
