The question of our national defense, always a difficult one, is now complicated by financial stringency, which imposes upon Congress a rigorous economy, while the construction and arming of forts and war ships necessarily demand an enormous expenditure.
Yet the nation must be prepared for defense as soon as possible, for no one can say when we may have to take up a gage of battle. Is it, therefore, possible to devise a secondary system of defense, which can strengthen without supplanting our primary system, and can be rapidly developed at a very moderate cost, and yet be of sufficient power to afford defense to our most exposed points until enough of time and treasure may be expended to bring to completion our permanent defensive system, of which the powerful work at Sandy Hook is so magnificent an example?
As a partial answer to this question, the following suggestions are submitted, as containing matter not unworthy of consideration, with the claim that the facts and principles relied on are well known, and are manifested in the daily routine of civil and social life.
The problem of closing waterways by artillery fire alone, since the application of steam and armor to ships of war, has proved a very difficult one, as has been frequently demonstrated, notably by us during our civil war, when the passage of the Mississippi River was forced by the Union’s wooden ships at its lower forts, at Port Hudson and Vicksburg; and while the defenders there had neither the formidable guns, explosives, or projectiles, nor the appliances for securing accuracy of fire, of to-day, yet neither were they opposed by ships as strongly armored or armed, or as swift, as are those ships which now might assail or attempt to run by our new forts. A further evidence of the inability of forts to protect waterways by artillery alone has been recently furnished by the facility with which Mello’s ships passed in and out of port at Rio de Janeiro in defiance of the three formidable forts at its entrance.