The Confiance was launched on the 26th of August, and Sir George Prevost having reason to believe that the efforts which were making for her equipment would enable Captain Fisher to take the Lake in the course of a few days, proceeded, on the 30th, to inspect the first brigade of troops quartered at Chambly; and on the 31st. established his head-quarters at Odell Town, close upon the enemy's frontier. Having here received information that General Izzard had suddenly quitted his position at Champlain Town, and had marched with a body of troops in the direction of Niagara, evidently for the purpose of joining General Brown, who had established a footing on the Niagara frontier, and was pressing upon Lieutenant General Drummond, Sir George Prevost determined to lose no time in entering the enemy's territory, (even though our fleet was not ready to co-operate,) in the hope by this movement of checking General Izzard's progress, and of thus making a diversion in favour of General Drummond. Our troops accordingly crossed the frontier line, and on the 3d of September took possession of Champlain Town, which the enemy had abandoned on their approach. Our forces advanced the following day to Chazy and Simpson's Inn, about eight miles from Plattsburg, where they halted on the 5th. Previously to this advance Captain Fisher, who had superintended the building of the Confiance, and whose local knowledge would have rendered his services peculiarly useful in the joint operations contemplated, had been suddenly and unexpectedly superseded by Sir James Yeo in the command of our naval force on the Richelieu, and Captain Downie had been appointed to succeed him. This officer did not arrive at Montreal from Lake Ontario until the 3rd September, and on the following day repaired to Isle aux Noix to superintend the equipment of the new ship. On the 5th of September, the day on which the troops halted at Simpson's Inn, an interview took place between Sir George Prevost and Captain Downie, when the latter assured the Commander of the forces, that his flotilla would be ready to co-operate with the army in less than forty-eight hours; that he had correctly ascertained the state and condition of the enemy's fleet; and that in consequence he entertained no apprehensions of the result of an action. Sir George Prevost then explained to Captain Downie the reason of his having pressed forward before the latter was ready. On the following day, the 6th September, the army advanced to Plattsburg, and took possession of that part of it situate on the northern side of the Saranac, the enemy's troops having retreated thence to the south side, and to their fortified position on the crest of the hills.