; low down in west thick with
haze; on the north the rays converged to a point still lower; lightning
still visible in south. This is an aurora in the west.

11th. Fine clear morning (N.-E.); same all day; no lightning visible
to-night, but a bank of clouds low down in south, 2d high, and streaks
of dark stratus below the upper margin.

12th. Fine and clear (N.-E.); noon, a well defined arch in S.-W., rising
slowly; the bank yellowish, with prismatic shades of greenish yellow on
its borders. This is the O. A. At 6 P.M., the bank spreading to the
northward. At 9 P.M., thick bank of haze in north, with bright auroral
margin; one heavy pyramid of light passed through Cassiopaea, travelling
_westward_ 1 1/2d per minute. This moves to the other side of the pole,
but not more inclined towards it than is due to prospective, if the
shaft is very long; 11.10 P.M., saw a mass of light more diffuse due
east, reaching to _Markab_, then on the prime vertical. It appears
evident this is seen in profile, as it inclines downwards at an angle of
10d or 12d from the perpendicular. It does not seem very distant.
12 P.M., the aurora still bright, but the brightest part is now west of
the pole, before it was east.

13th, 6 A.M. Clear, east and north; bank of cirrus in N.-W., _i.e._,
from N.-N.-E. to W. by S.; irregular branches of cirrus clouds, reaching
almost to south-eastern horizon; wind changed (S.-E. fresh); 8 A.M., the
sky a perfect picture; heavy regular shafts of dense cirrus radiating
all around, and diverging from a thick nucleus in north-west, the spaces
between being of clear blue sky. The shafts are rotating from north to
south, the nucleus advancing eastward.

Appearance of the central vortex descending at 8 A.M., July 13th, 1853:

In Fig. 18, the circle represents the whole sky from the zenith to the
horizon, yet it can convey but a very faint idea of the regularity and
vividness of this display. The reflected image of the sky was received
from a vessel of turbid water, which will be found better than a mirror,
when the wind will permit.

[Illustration: Fig. 18]

At noon (same day) getting thicker (S.-E. very fresh); 6 P.M., moon on
meridian, a prismatic gloom in south, and very thick stratus of all
shades; 9 P.M., very gloomy; wind stronger (S.-E.): 10 P.M., very black
in south, and overcast generally.

14th. Last night about 12 P.M. commenced raining; 3 A.M., rained
steadily; 7 A.M., same weather; 8.20 A.M., a lin