A permanent work on Point Edward Sarnia, to command the St. Clair River, has been suggested, and it has been recommended that the defences of Fort Maldon and Bar Island should be made permanent works, but other engineers have considered it unwise to erect fortifications at Sarnia or Amherstburg, and contend that the Niagara and Detroit frontiers are too much exposed to be tenable by any works. Guelph should also be rendered worthy of its important position. London, being a railway station, is, in event of a war, an important point to hold for the carriage of troops; and although there is no ground close at hand admitting of tenacious grip, there is a tolerably good line of defence at Konoska, which the spade could convert into a fair position. When we come to consider the condition of the Toronto district it becomes apparent that two points require especial attention--Fort Dalhousie and Port Colborne. It is unwise to leave these places without defences to cover the garrisons, and to enable them to protect the shore against desultory operations and isolated detachments. Domville and Maitland are open to predatory attacks which might be prevented by ordinary fortifications or earthworks on eligible sites. It is impossible to defend a canal; but much good might be done by enlisting the employés on the Welland as a sort of guard, whose local knowledge would be available in time of danger. Although, as I have said, strong reasons are urged against any outlay for the defence of the Niagara frontier, on the ground of its exposure, there are distinguished authorities who insist that a permanent work is required at Fort Erie; and who contend that another fort should be erected at Niagara, in support of an entrenched camp, which would exercise a most powerful influence over the movements of an invading force, particularly if there were gunboats placed on the Chippewa. One of the painful necessities of war between the United States and Great Britain would be the destruction of the suspension bridges over the river. Hamilton is generally considered as incapable of defence, but it lies in a district which presents two lines of hills capable of being adapted to defensive purposes, and earthworks there might be stiffly held, in case of attack, by the troops of the district, to enable the forces to concentrate and retire along routes previously determined. Toronto itself may be regarded as an open place equally incapable of defence by ordinary works; but it should not be left open to such a _coup_ by a single cruiser, as might be obviated by the erection of a fort on the site of the new barracks: and it would be necessary to construct a strong entrenched camp to cover it and protect the troops retiring before the enemy. A chain of earthworks might be placed on the elevated ridges which run from the Don River towards Humber Bay. A casemated fort on the island is also most desirable. Toronto has something more than its mere