Temperatures ranging from 50 to 70 minus were of frequent occurrence, and, on one occasion Back, after washing his face within a yard of the fire, had his hair clotted with ice before he had time to dry it. Every animal was driven away from the neighbourhood by the cold, except a solitary raven which swept once round the house and then winged his flight to the westward. On the 25th of April a messenger arrived at the fort with the news of the safe return of Sir John Ross to England, but Back determined to proceed with the journey for exploring purposes, taking one boat instead of two, and, with Richard King the surgeon, and eight men, he started for the Great Fish River on the 8th of July. [Illustration: BACK'S JOURNEY DOWN THE GREAT FISH RIVER] The voyage was a hazardous and adventurous one. For five hundred and thirty geographical miles the river was found to run through an iron-ribbed country without a single tree on the whole line of its banks, expanding into fine large lakes with clear horizons, most embarrassing to the navigator, and broken into falls, cascades, and rapids, to the number of no less than eighty-three, pouring its waters into the Polar Sea in latitude 67° 11´ and longitude 94° 30´; so that his explorations on the northern coast were confined to a section further east than Point Turnagain. The expedition met with its greatest danger at Escape Rapid, between Lake Macdougall and Lake Franklin, on the 25th of July. Here the stream was broken by a mile of heavy and dangerous rapids. The boat was lightened, and every care taken to avoid accident; but so overwhelming was the rush and whirl of the water, that she, and consequently those in her, were twice in imminent peril of being plunged into one of the gulfs formed in the rocks and hollows. It was in one of these places, which are fall, rapid, and eddy within a few yards, that the boat owed its safety to an unintentional disobedience of the steersman's directions.