EXTRA OBSERVATIONS OF MAGNETOMETERS, MARcH 29—Apnrit 7. 1843. 61 
NOTES ON THE AURORA BOREALIS. 
' Cley val eas 
March 29 An Auroral light was seen about 95 to NNW., assuming the form of a segment of a circle, which 
j became rather bright about 9° 50™, the light being homogeneous ; at 105 50™ the light was 
more spotted, but no pencils were visible. At 10% 25™ a meteoric light was seen, at first 
a rather faint, proceeding from a point 1° to the south of Zeta Orionis (which was then just seen 
| to about WSW. above the surrounding trees), passing between Castor and Pollux, and lost in a 
} nebula in the back of Leo Minor. It became gradually brighter till about 10" 35™, when its 
brightness perhaps equalled the most vivid pencils of an aurora, and gradually diminished in 
} intensity and length till altogether lost about 10" 55™. The breadth at Orion was about ite 
this being the brightest portion of the meteor, but increasing gradually upwards, filling the 
space between Castor and Pollux; the greatest length seen might be about 100.° There was 
no appearance of corruscations. This meteor, undoubtedly connected with the aurora, was 
| singular in every way, whether we regard its form, position, isolation, or duration. 
| The Aurora had disappeared at 12", 
April 5 9 30. Aurora, altitude about 35° or 40°; streamers and corruscations, brightest to N. by E. 
| 
| 
9 40. Bright auroral arch stretches from W. to NE., altitude 30°, sending streamers downwards to N. 
10 15. Splendid aurora, originally with a double arch, the greatest having an altitude of 80°, the other of 
60°, spanning 150° of horizon. An auroral pencil seen frequently in the same position as 
that observed on March 29, but never having the same duration. The aurora is brightest 
; to NE. by E., the E. extremity of the arch, although the moon being near that point renders 
it less obvious. A portion to the E., which is brightest, branches off in a cycloidal form. The 
arch is sometimes triple, the lowest being 10° altitude, with pencils of aurora between. 
: 10 20, Arches more broken, and sending pencils up to the zenith. Arches broken into pencils, vivid 
from W., and directed a little to the S. of the zenith. 
10 22. Arch altogether irregular to E. as if broken into small arches, with a bright mass to NNW. and 
NW., extending to the W. extremity of the arch, but broken at the N.; the dark space below 
having pencils occasionally. 
10 25. Pencils to W., very bright ; arch strangely irregular, the light space being about 15° broad, and 
generally cycloidal at the terminations on the horizon. A long pencil seen frequently to W., 
as at 15™. 
11 11. The arch now spans 130° of horizon, is 30° altitude, and 5° broad, with broad brushes of light 
below ; the western extremity of the arch is bent inwards towards the north. 
| a 11 34. Arch only 10° altitude. 
12 30, Arch spans 130°, 12° altitude, 6° or 7° broad, and the form is cycloidal: no pencils at present. 
12 45. Again double arches, but close to each other; occasionally pencils from the NE. extremity. The 
moon is below the arch to WNW., and has a corona the breadth of its own diameter; the sky 
is beautifully clear, the stars appearing very brilliant, and no clouds are to be seen. 
13 0-5, Strong pencils from the E. extremity of the arch. A new arch commencing at NNW., is spring- 
ing up with the other; its altitude is 8°. The apex of the greater arch is about N. 5° W., and 
the breadth is increasing from 3° to 10°—much flickering. 
14 0. Auroral arch much broken—altogether diminished ; patch of cloud to NNW. 
April 515 30. The sky became! quickly covered with scud—the aurora gone. 
April 714 0. An anrora to N., in the form of portion of an arch, 10° broad, reaching from W. to NNW.— 
; flickering, but no pencils. 
16 0. Faint auroral mass of light, 8° hich and broad, variable in brightness, flickering. 
16 35. Auroral light still flickering to NNW.—-strong twilight. 
_ MAG. AND MET. oBs. 1843. Q 
