In the following March a party of six--David, Mawson, Mackay, Adams, Marshall, and Brocklehurst--prepared for the ascent of Mount Erebus, the volcano, then active, discovered by Ross and named after one of his ships. The crater rim was only a few miles distant, and during the first three days the party could be seen from the camp by means of a powerful telescope--tiny black specks struggling up the ice-clad slopes. Three craters were discovered, the youngest and highest of which was found to be thirteen thousand three hundred and fifty feet above sea level.[3] During the ascent the party nearly perished in a gale which blew their tents into tatters. The crater rampart was finally reached, however, and a number of excellent photographs were made. During the entire stay at Ross Island the steam column from the crater furnished the means whereby the direction of the upper currents of air might be instantly noted, and the condition of activity did not differ materially from that observed in Stromboli. When the barometer was low the steam column was heavier and denser; the glow of light was also brighter. With a high barometer, on the contrary, the conditions were reversed, the steam column was insignificant and the glow was scarcely visible. As a rule, the ascending column of steam was projected three thousand feet or more before it was caught by the upper air current. Measurements showed the principal crater to be half a mile in diameter and nine hundred feet deep. Great deposits of sulphur and pumice were observed. In the last week of October a party composed of Shackleton, Adams, Marshall, and Wild started on the trip to discover the south pole. The journey to the point farthest south occupied seventy-three days. After a few days out from the winter quarters no bare rock was seen--the landscape being one of ice and snow. Shackleton's journal of January 8 notes the fierce gales blowing at the rate of seventy or eighty miles an hour, while the temperature had dropped to "seventy-two degrees of frost." "We are short of fuel," he writes, "and at this high altitude, eleven thousand six hundred feet, it is hard to keep any warmth in our bodies between the scanty meals. We have nothing to read now, having left behind our little books to save weight, and it is dreary work lying in the tent with nothing to read, and too cold to write much in the diary."