Under the actual conditions, the proposed ascent of the river bore a very different aspect to the commanding naval officer on the spot from that which presented itself to the fond imaginations of the officials in Washington. The question now was not one of fighting batteries, for there was no reason as yet to expect anything heavier than the fleet had already overcome with ease; it was the far more difficult matter of communications, in the broadest scope of the word, to be maintained over a long, narrow, tortuous, and very difficult road, passing in many places close under the guns of the enemy. "As I stated in my last dispatch," wrote Farragut to the department after his first visit to Vicksburg, "the dangers and difficulties of the river have proved to us, since we first entered it, much greater impediments to our progress, and more destructive to our vessels, than the enemy's shot. Between getting aground, derangement of the machinery, and want of coal, the delays in getting up the river are great." To take the defenses in the rear, and in their then state to drive the enemy out of them, was one thing; but to hold the abandoned positions against the return of the defenders, after the fleet had passed on, required an adequate force which Butler's army, calculated by McClellan for a much narrower sphere, could not afford. Coal and supply ships, therefore, must either run the gantlet for the four hundred miles which separated Vicksburg from New Orleans, or be accompanied always by armed vessels. The former alternative was incompatible with the necessary security, and for the latter the numbers of the fleet were utterly inadequate. In fact, to maintain the proposed operations, there would be needed so many ships to guard the communications that there would be none left for the operations to which they led.