sq as to point to 144°. Another beam darted from 257°, and joined the former
one. The arch, thus formed, descended gradually against the wind. There
was only a slight lateral motion perceptible while it remained across the
zenith ; but when it had sunk to about 60° from the horizon, an interior motion
rushed from each of the extremities towards the middle, and at the place of
contact the greatest commotion was, excited, and the prismatic colours were
exhibited- The motion of the needle 8 minutes eastward. This arch
disappeared at an elevation of 25°, Between llh, and midnight, sounds
were repeatedly heard resembling the hissing of a musket-balk? or the
shaking of a thin pliant stick in the air, which were at first supposed
to have been occasioned by the motion of the Aurora. Mr. Wentzel,
however, who assured us that he had often heard the noise of the Aurora,
said these sounds were very dissimilar to that which the Aurora makes, and
that he supposed the noise to be occasioned by the cracking of the snow, in
consequence of a great decrease in temperature immediately after the two
preceding days of mild weather. I was of the same opinion, from the circumstance
of a similar noise having been heard after midnight coming from
the eastward, in which quarter there was not the least appearance of Aurora,
and when only a faint motionless beam was visible to the eastward. This
opinion was further confirmed on the following morning, when similar sounds
were distinctly heard at the time the sun was shining bright, and there was
not any symptom of Aurora.
12th. At midnight, faint streams from 88° directed towards the zenith.
Some patches visible in other parts of the sky.
13th. At midnight, a beam shot from 302° across the zenith tot 88°.
Another extended to the zenith, whose lower extremity bore 290°. A
horizontal band from 834° to 257°. The needle since nine moved 1° 25'
westward.
14th. At nine p. m- a faint beam at 99° pointing towards the zenith. At
midnight a faint low stream from 76° to 110°. No change in the needle.
15th. At midnight, waving streams from 110° to 144°, and from 189° to 212?
elevated 20°, No change in the needle.
16th, At 3h. p. m- some clouds appeared about 279°, which bore a strong
resemblance to the Aurora, particularly one of the beams, which extended 40°
towards the zenith. The needle moved 18'westward, between 3h. and 5h. p. m.
565
At midnight, a faint stream of Aurora reached from 65° to 279°, elevation 25°.
No change in the needle.
19th. At 9h. p. m. a faint arch from 121° to 212°, ,elevated 25Vt At midnight,
low streams from 144° to 324°, which nearly encircled the horizon.
Seven beams were projected upwards, from different parts of this zone. Their
points did not meet in the zenith, but terminated about 3° short of that part.
The whole appearance strongly resembled an artificial globe, the zone being the
equator, and the beams the meridian lines. The needle moved 25' eastward
between nine and midnight, but I observed it to move gradually westward, as
these beams were disappearing. Immediately after they had ceased to be
visible, an arch was exhibited crossing the zenith, in the direction of the
magnetic meridian. The needle still continued to recede westward, until it
rested nearly in the position at which it was at 9h. p. m.
20th. At 9h., an arch from 99° to 27.9°. A beam at 99° pointing towards
the zenith. A stream from 257° to 290°. At midnight, a low stream from
302° to 54°, along, which the interior motion passed very rapidly. The needle
moved 1° westward. The sky was overspread with fleecy clouds.
21st. At llh. a. m., some clouds lying parallel to the horizon between 345°
and 76° strongly resembled the Aurora. At 9h. p„ m. Aurora in a bright arch
from 99° to 280°, passing within 3° of the zenith. This descended to the
eastward against the wind. At midnight two beams darted from 144°, one
shot across the zenith to 290°, the end of the other curved round just beyond
the zenith, and, in a few minutes, both of them rushed back to 144°, and then
disappeared. A waving stream reached from 279° to 99°, elevated 12°, several
beams were projected upwards from this stream. A beam darted from 54°
across the zenith,, and immediately after this flash, the lower extremity of the
beam moved round to 99°, and an arch was formed from 99° to 279?. The
needle moved nearly 2° westward, between nine and midnight. At 12h. 30m.
Aurora generally diffused over the sky. A brilliant arch Grossed the zenith
from 279° to 110°; this soon afterwards separated, so as to form three arches
parallel to each other. Some beams laid at right angles to this arch, which
had come from the eastern horizon or bearing 54°. No motion in the needle
perceptible.
22nd. At 9h., Aurora in an arch from 290° to 88?, a bright band from 88p
to 65°. At midnight, the following, appearances of the Aurora were-visible