On the 29th of December, Cook ascertained positively that the iceberg was joined to no land. He therefore decided to proceed eastward as far as the parallel of Cape Circumcision, that is, if no obstacle prevented him. He had scarcely put this resolve into execution when the wind became so violent, and the sea so rough, that navigation, in the midst of floating ice, which crashed with a fearful noise, became most perilous. The danger increased, when a field of ice extending beyond the range of vision was seen to the north. There seemed every prospect of the ships being imprisoned for many weeks, "hemmed in," to use the expression of whalers, if indeed they did not run the risk of being crushed at once. Cook neither tried to run to the west or east, he steered straight for the south. He was now in the latitude attributed to Cape Circumcision, and seventy leagues south of the position assigned to it. Hence he concluded that if land existed as stated by Bouvet (which is now known to be a fact) it could only be an inconsiderable island, and not a large continent. The captain had no further reason for remaining in these latitudes. In 67 degrees 15 minutes southern latitude a new ice barrier, running from east to west closed the passage for him, and he could find no opening in it. Prudence enjoined his remaining no longer in this region, for two-thirds of the summer were already passed. He therefore determined to seek, with no further delay, the land recently discovered by the French. On the 1st of February, 1773, the vessels were in 48 degrees 30 minutes south latitude, and 38 degrees 7 minutes west longitude, very nearly the parallel attributed to St. Maurice Island. After a fruitless cruise, productive of no results, they were forced to conclude, that if there really were land in these latitudes it could only be a small island, otherwise it could not have escaped their search. [Illustration: New Zealand war canoe. (Fac-simile of early engraving.)] On the 8th of February, the captain found to his dismay that the _Adventure_ was no longer sailing with him. He waited in vain for two days, firing at close intervals and keeping great fires upon the deck all night. The _Resolution_ had to continue her voyage alone. On the morning of the 17th of February, between twelve and three o'clock, the crew witnessed a magnificent spectacle, then first seen by European eyes. It was an aurora borealis. "The officer of the watch," says the narrative, "noticed that from time to time rays left it in spiral and circular forms, and that then its brilliancy increased, which gave it an extremely beautiful appearance. It appeared to have no particular bearing, but remained motionless in the heavens, which it filled entirely from time to time, by throwing its light to all parts."