It is by no means impossible, after all, that what seemed at first to be a national calamity, and which rendered yesterday a memorably dark day in the experience of every patriot, was after all a substantial and crowning advantage, anticipated and provided for in the plans of the Administration. Its policy has been uniform and consistent-to protect the property of the Government, and enforce its laws. It will yield nothing belonging to it unless dispossessed by superior force, but it will not weaken the reputation of its military arm, by a reckless waste of men or means in the maintenance or attempted recapture of any comparatively valueless position. This arm is wielded by that illustrious Chief and Patriot, whose forty years of active service have never known dishonor or defeat, who, in the disappearance of our great leaders, is providentially left to us, and under whose guidance, though we may not for the time be advised of his plans, we are always sure of being led to substantial success.

It is altogether probable that Fort Sumpter could not, at any reasonable cost, have been relieved, after Mr. LINCOLN assumed the reins of Government, till he had collected the Army and Navy, dispersed by Mr. FLOYD, in order to render Washington and the forts and magazines at the South an easy prey, and could assume something like vigorous offensive action. It was important that Fort Sumpter should be retained as a point upon which to concentrate the military strength of the rebels, securing to him precious hours in which to concentrate his forces upon more important and menaced points. To abandon, it would instantly relieve a large force to operate against Washington and Fort Pickens. To hold this force inactive till they could be reinforced in a manner to defy attack, was a master-stroke of policy, and does credit even to Gen. SCOTT’s military reputation.

This advantage being gained, the Administration was then prepared to test the question whether the Confederated States would allow the sending of supplies to a handful of famished soldiers, cooped up in Fort Sumpter. To relieve their wants was an act of mercy as well as peace. To prevent it, would be an act of war. This war the rebels have inaugurated. Major ANDERSON’S orders were to act as he did at Fort Moultrie—to consult the emergency; to yield, if necessary, to superior force. The fleet did not render assistance, as it could not, without the risk of being disabled, and, perhaps, destroyed. [The] Government was too weak in its naval arm to encounter any such risks. It would interfere with its proper command of the sea, and with its plans, to commence an immediate enforcement of the revenue laws at the ports of the rebel States. Fort Sumpter, as a strategic point, is of no sort of consequence. It was constructed solely for defence against foreign invasion, which is not contemplated by the Government.

The port of Charleston, we learn by way of Montgomery, is blockaded. Every vessel entering or leaving it is to pass the surveillance of a ship-of-war. No wonder that “the Charlestonians regarded with execration the fleet that refused to come to the rescue of the gallant ANDERSON.” It was not the plan of the Administration that they should go to his rescue at too great a peril. It was from the start destined to an entirely different field and mode of action. Neither the retention or surrender of Fort Sumpter could have any bearing on the policy the Government had marked out for itself. This was an isolated case, that stood solely on its own merits. [The] Government could not allow its Flag to be disgraced by retreat. It is strengthened in every part by the surrender of the Fort. It may not attempt, at present, its recapture, but will notify the Confederated States that, till it is restored, the commerce of Charleston must pass over the deck of a ship-of-war.

The first act in the drama which has terminated in the surrender of Fort Sumpter, instead of being a defeat, is, when we come to look at its effects, a most brilliant success. It has thrown upon the Confederated States the entire responsibility of commencing the war. It has given us time to arm for offensive operations, and to collect and to place before every Southern port a fleet sufficient to enforce the revenue laws, and to protect our commerce from Southern pirates. We still hold every point of value in the Gulf—Fort Pickens, Key West and Tortugas. We turn the Confederated States upon themselves. We hold the command of the sea, upon which they cannot even float Alderman BOOLE’S scows. Their armies, which they have collected and armed with such cost, they may turn against each other, to help to stifle the little freedom of thought or expression that may yet exist. They are harmless against us. The little commerce that may still seek their ports must submit to our revenue laws.

All this the Confederates at Montgomery may, in their impotent rage, contemplate with the same execration that the people of Charleston did the fleet that refused to expose itself to fire. Water is not their element. We command the avenue upon which their existence depends. They have commenced the war. We now propose to give them a taste of our power without exposing ourselves to their attacks. Mr. JEFFERSON DAVIS had good cause for being sick in bed at the reception of the news. The magnitude of the advantage gained at Washington, and the utter inability of the Confederate forces to cope with us in the arena we have chosen in which to carry on the contest, accounts for the lowered tone adopted at Montgomery and the feeble salvo of seven guns at their triumph. We are now prepared for a contest in a field in which we hold their lives in our hands, and on which they cannot harm us to the extent of a hair. We are prepared to follow up such a contest till they are entirely satisfied.