The works recommended by the Board, consist of a single fort, costing $600,000, at Rouse's Point, on the extreme frontier, and unfortified depots at Plattsburg and Albany.

But is this sufficient to accomplish the object?
If the hostile army should pass the extreme frontier barrier, what is to retard his advance,--what defensive works are to protect the debouche of the Northern canal, or even to save the great central depot?
We know of no foreign engineer who has recommended less than _three_ lines of fortifications for the security of a land frontier; and Napoleon, the Archduke Charles, and General Jomini, agree in recommending at least this number of lines.
There may be circumstances that render it unnecessary to resort to a three-fold defence throughout the whole extent of our northern frontier; but upon our main line of communication with Canada,--a line of maximum importance both to us and to the enemy, we know of no reason for violating the positive rules of the art,--rules which have been established for ages; and sanctioned by the best engineers and greatest generals of modern times.
Ticonderoga has more than once stayed the waves of northern invasion; and we know of no change in the art of war, or in the condition of the country, that renders less important than formerly the advantages of an intermediate point of support between Albany and the Canadian lines.
Indeed it would seem that the connection of the Hudson with the lake by the northern canal had even increased the value of such a point.
It would seem, moreover, that the great value of a central depot near Albany would warrant a resort to the best means of security which can be afforded by defensive works.

Here we already have one of our largest arsenals of construction; here are to be located magazines for the collection and deposit, in time of peace, of gunpowder; here, in time of war, is to be formed the grand military depot for our whole northern armies; and here is the point of junction of the lines of communication of our northern and eastern states, and the great central rallying point where troops are to be collected for the defence of our northern frontier, or for offensive operations against Canada.

Such a place should never be exposed to the _coup-de-main_ of an enemy.

The chance operations of a defensive army are never sufficient for the security of so important a position.