In the summer of 1812, when Thompson arrived at Fort William after his last journey from beyond the Rockies, he was in the forty-third year of his life. It was twenty-eight years since he had landed as an apprentice on the shores of Hudson Bay; and twenty-three years since he had actively embarked on his career as a surveyor. During all this time he had been constantly accumulating materials for his great map of the North West. His work was now complete; so that instead of returning to the interior, he joined the annual brigade of great canoes bound for Montreal. Thus did David Thompson bid adieu forever to the Great North West. CHAPTER VIII LAST YEARS In 1812, hostilities had broken out between the British Empire and the United States, and the flame of war was raging along the international border. In the St. Mary's river, the voyageurs of the North West convoy with which Thompson was travelling feared that American troops might intercept their rich cargo of furs, but they passed through the narrows without being molested and were soon safe among the islands of the north shore of Lake Huron. From thence they made a speedy passage up the French river and down the Ottawa to Montreal. His country endangered, Thompson accepted a commission in a battalion of infantry then being raised by his old colleague Roderick Mackenzie, but it does not appear that he was ever on active service. The winter of 1813-4 he spent in preparing a final draft of his map. This map, in which was embodied the record of his life work, became a proud possession of the North West Company. For many years it occupied a place of honour on the walls of the banqueting hall at Fort William. When the war was over, Thompson was selected as British representative on the commission which surveyed the international boundary from the River St. Lawrence to the Lake of the Woods. This task occupied him for the next ten years, and was concluded in the autumn of 1826. At this time, Thompson planned to offer to the public an edition of his map, and even went so far as to prepare a prospectus. This prospectus is worth reproducing, because it sets forth in Thompson's own words the achievements of his career as a geographer: "PROSPECTUS" "To be published in England, by David Thompson, a new and correct map of the Countries in North America; situated between the parallels of 45 degrees; and 60 degrees of North Latitude; and extending in longitude from the east side of Lake Superior, and Hudson's Bay, quite across the Continent to the Pacific Ocean; and from his own local knowledge; being the result of 22 years employment in discovering, and laying down the several rivers, lakes, hills and mountains on this extensive tract of country; many parts of which had never before been explored; these discoveries were only finished in 1812. The whole founded on astronomical observations, the author being an astronomer by profession.