The next expedition to the north coast of America was a private one. A Committee raised the necessary funds, and the plan was to descend a river which was supposed to have its rise in the Great Slave Lake, and to fall into the Polar Sea. The object was to obtain tidings of, and to succour, the expedition of the Rosses, which had not been heard of for some years. Captain Back received the command, and his companion was Dr Richard King, a medical man. Only three other men were taken from England. The explorers started in February 1833, 15 men were engaged, and the expedition reached the Great Slave Lake. The source of what Back called the Great Fish River was discovered, but its course was found to be tortuous and full of rapids. Back, therefore, caused two boats to be built, specially adapted for river navigation, and for being taken over the portages. They were sharp at both ends, with good beam, and plenty of floor for stowage. They were 30 ft. long over all, 24 ft. keel, with extra oars, masts, and tillers. Their lower parts were carvel, and the upper clinker-built. Runners, plated with iron, were fixed on either side of the keel, so that they could easily be drawn over ice by six dogs and two men. Eight men formed the crew. Captain Back and Dr King were thus well equipped for discovering the course of the Great Fish River. But at this juncture the news was received of the safety of the Rosses, and it did not seem justifiable to do more than descend the river to its mouth. This Back did, finding that the river has a violent and tortuous course of 530 miles, sometimes expanding into large lakes, and having 83 falls and cascades. The estuary was surveyed, together with a large island named Montreal. Back intended to have traced the coast as far as Cape Turnagain, but only got 15 miles westward to Capes Richardson and Maconochie. Captain Back and Dr King both published narratives of the Great Fish River expedition. There still remained unexplored the coast line from Franklin’s furthest to Cape Barrow on the west side, and from Cape Turnagain to Repulse Bay on the east. The Hudson’s Bay Company resolved to undertake these discoveries. Peter Warren Dease, who had assisted the Franklin Expedition, and Thomas Simpson were selected for the duty. Simpson was a very intelligent and energetic young Scot, born at Dingwall in Ross-shire in 1808. Dease was much older. The equipment was arranged at Fort Chipewyan. The two boats were clinker-built, 24 ft. keel by 6 ft. beam, each with a small oiled-canvas canoe. They were named the _Castor_ and _Pollux_. Thirty bags of pemmican, each weighing 9 lb., and 10 cwt. of Red River flour were taken for the whole season. The daily ration per man was 3 lb. of pemmican.