LAST VOYAGE OP CAPT. ROSS. 
165 
of the upper deck. The bread store was examined and found 
to be in good condition, the whole weighing 2700tbs. 
At 8 p.m. the aurora was observed to begin in two concentric 
arches; the greatest arch from the east to west, passing through 
the zenith; the smaller arch south of the large one, at an altitude 
of 45°, shooting fine rays from all parts, but most brilliant from 
the western. These arches disappeared at half-past eight, and 
another most brilliant one was seen north of the zenith; the 
centre passing through the pole star, the extremities touching 
the eastern and western horizons, emitting fine rays with all the 
prismatic colours. This arch was soon broken, and the aurora 
flitted about, in beautiful coruscations in the north western part 
of the heavens, shifting round to the southward ; the moon shone 
unclouded at the time, and the aurora was seen sometimes passing 
her, eclipsing her in splendour. At 9^30' the aurora disappeared, 
the weather moderate at the time, with some light fleecy clouds 
in the sky, which had a dark appearance when passing under it. 
It blew hard from the westward in the morning, but moderated 
towards evening; the wind shifted to the southward next day 
with moderate weather. 
Very little attention had hitherto been paid to the geological 
character of the country, as the business of the ship had hitherto 
absorbed all the time of those officers, who were enabled to make 
the necessary observations in order to determine the general 
structure of the island. A considerable portion of the north and 
east coasts bespoke the existence of primary rocks, the hills 
rising to an average height of one thousand feet, and presenting 
acute summits, declining by sharp prolonged ridges. There 
was apparently a ridge of hills of the trap formation, skirting the 
shore for the space of about four miles, and interrupted in two 
places; this ridge rose to about half the general elevation of the 
island, and presented a vertical prismatic fracture at the summit 
accompanied by the usual rapid slope below. 
From the general character of the land, it may be concluded 
that the country in general is of primary formation. From the 
forms which the mountains assumed in the interior, it is most 
probable that they consisted of granite, but no certain conclusion 
