On 29 March 1613, arriving back in New France, he first ensured that his new royal commission be proclaimed. Champlain set out on May 27 to continue his exploration of the Huron country and in hopes of finding the "northern sea" he had heard about (probably Hudson Bay). He traveled the Ottawa River, later giving the first description of this area. Along the way, he apparently dropped or left behind a cache of silver cups, copper kettles, and a brass astrolabe dated 1603 (Champlain's Astrolabe), which was later found by a farm boy named Edward Lee near Cobden, Ontario. It was in June that he met with Tessouat, the Algonquin chief of Allumettes Island, and offered to build the tribe a fort if they were to move from the area they occupied, with its poor soil, to the locality of the Lachine Rapids.