“On subjects which have a mere speculative importance, there is no danger in giving rein to speculation; but on those of such real and intense practical importance as the security against hostile aggression of the great city and port of New York, it is not admissible to set aside the experience of the past, or the opinions of the best minds who have devoted themselves to such subjects.  A means of defence, sanctioned by its being confided in to protect the great ports of Europe—­which has protected the great ports of Russia against the most formidable naval armament that ever floated on the ocean, has a claim upon our confidence which mere criticism cannot diminish; and a claim to be adhered to in place of all new ‘systems,’ until time and trial shall have necessitated (not merely justified) the change.”

“If, then, we refer to the practice of other nations, to find what has been judged necessary for the defence of important ports,—­to experience, to find how such defensive systems have stood the test of actual trial,—­we may draw useful conclusions with regard to what is now required to defend New York.  We shall find at Sebastopol—­a narrow harbor, which owed its importance to its being the great naval depot of Russia on the Black Sea—­an array of 700 guns, about 500 of which were placed in five ‘masonry-casemated’ works (several of them of great size), and the remainder in open batteries.  These defensive works fulfilled their object, and sustained the attack of the allied fleet, on the 17th of October, 1854, without sensible damage.”

“The facility with which seaports are attacked by fleets—­the enormous preparations required—­the great risks encountered in landing a besieging army on the coast of a formidable enemy (while, for protection against the former species of attack, costly works are necessary, and against the latter, field works and men can, in emergency, afford protection), naturally caused the Russians to make these water defences their first object.  Yet, though almost unprotected on the land side, Sebastopol resisted, for a whole year, an attack on that quarter; and illustrated how, with plenty of men and material, an energetic and effectual land defence may be improvised, where the sea defence is provided for, as thoroughly as it was at that place.”

“Let Cronstadt be another example.  Great as was the importance of its defence to Russia, it was not greater,—­it was by no means as great, as that of New York to our own country.  This port, and military and naval depot, was defended (in its main approach) by upwards of 600 guns, 500 of which were mounted in five ‘masonry-casemated’ works; the remainder in an open barbette battery, which enfiladed the main channel.  This number is formidable in itself; yet the same number mounted in New York harbor would not afford anything like such a formidable defence as was found at Cronstadt, owing to its great area, and long line of approach, compared with the latter.”