Kingston would also be a point of attack, as much from its importance to us as from its value to the enemy, who would, by the possession of it, command the Rideau Canal, which connects the river Ottawa with Lake Ontario. It is plain that if the points liable to attack were left in their present state, there would be little hope of our ability to defend them by fighting in the open field. United, the Americans are to the Canadians as about eight to one. The State of New York alone is as populous, and is richer, than the Canadas. Great Britain, thousands of miles away, could not hope, by any expenditure of money, or by any display of military skill, to equalise the conditions of the assailants and the defenders of her sovereignty. The engineers are right, therefore, in the argument, that the only way of enabling the Canadians and their British allies to make way against the Republicans, is to establish fortified works supported by or supporting a naval force. The Americans have an idea that it is possible to carry on operations during winter. Our engineers start with the assumption that it is impossible to do so on any large scale, and that it is out of the question for some five months of the year in Canada. The obstructions to siege operations might not be so serious, but they would be so considerable as to render the undertaking of them exceedingly hazardous, and little likely to succeed. The question, then, presents itself whether Canada can be defended for the time in each year during which operations are practicable, and if so, in what manner the defence is to be conducted. Our military authorities are of opinion that Canada can be defended. The Americans, as far as I could judge from their remarks on the subject, and from conversations with several of their officers, conceive that Canada lies at their mercy whenever they choose to attack it. As a chain of great frontier fortresses could not be established or maintained, the means suggested for the purposes of defence are principally of a provisional character. To meet the flood of invasion, it is proposed to cover the approaches to the vulnerable points. Ottawa, Montreal, and Quebec would be defended by forces posted in earthworks, and covered by entrenched camps at Prescott and Richmond, and other suitable places. If we examine the modes of proceeding to which the enemy would probably resort, we shall find them classified under five heads. First, a naval descent on Goderich. Second, the descent of a force between Detroit and London. Thirdly, the descent of a force on Niagara. Fourthly, the passage of a force between the St. Lawrence and Ogdensburg. Fifthly, an attack by several columns converging in concert on a point between Derby and Huntingdon, with a view of concentrating on Montreal, and cutting the communications with Kingston as well as with Quebec. Let us take a glance at the present state of the principal points, and consider what is needed to improve their condition.