Causeway, about 8 miles from the city, and Rosedew Island, or Coffee Bluff, 11 or 12 miles from the city, on the Little Ogeechee, which is guarded, without field works, by a light battery of six guns and one rifled 6 pounder piece. At the Isle of Hope Causeway a short line of rifle pits (with a position for a field gun) have been thrown up. It must be evident that should any one of these outworks fall into the hands of the enemy all the rest can be taken in reverse and must necessarily be evacuated at once, or else a battle must be fought outside of our interior line of defenses to maintain the line of outworks, which is contrary to the clear interests of the defenders, who must be supposed to be much inferior in numbers to the assailants. The enemy being then in possession of the line of outworks would establish a number of heavy batteries from Carston's Bluff toward Fort Boggs, from which he would completely command the first line of batteries on the river, namely, Fort Jackson and Batteries Lee and Lawton and the naval battery, the two first being taken directly in rear at a distance of from 1 1/8 to 1 1/4 miles.

Fort Jackson, I will remark, is a very weak old work; its masonry scarp being almost entirely exposed to the enemy's heavy guns on the river, and its flanks and rear loop-holed brick walls, some 2 feet thick and 25 feet high, are exposed almost to their foundations to the enemy's batteries from the line already indicated. It is my opinion that so defective a work could not resist more than a few hours' cannonade. It must follow therefore that the enemy would not be long in silencing the works on the river which command the obstructions, which last could then be removed at leisure, leaving the river open to the fleet to the immediate vicinity of the city, or until arriving under fire of the Hutchinson Island Battery of three 32-pounders, of the Bay Battery of one 8-inch columbiad, three 32-pounders, and two 10-inch mortars, and of Fort Boggs, on the bluff, three-quarters of a mile from the channel, armed with one 10-inch columbiad, seven 32-pounders, and one 10-inch mortar; that is, in all, fifteen guns and three mortars, which could not be expected to interpose a substantial obstruction or delay the enemy long in his passage to the city, in which event the garrison of the city would be exposed in the rear to the enemy's heavy naval armament and in front to an invading land force, and consequently the contest, if attempted, would scarcely be of long duration.

Thus it is clear the safety of Savannah is made to depend upon the fate of the line of outworks, which in military engineering are only intended as subsidiaries to delay the movements of the enemy until the necessary preparations are made in the main work to repel successfully the impending attack, just as pickets and advanced guards of an army are thrown out to arrest the movements of an enemy until the army, duly warned of the advance, can take up positions in line of battle. If the line of obstructions had been placed near the lower extremity of Hutchinson Island, immediately under the guns of the battery at that point and those of Fort Boggs and of two revolving iron-clad land batteries, one on the western and the other on the eastern bank, near Screven's Ferry Landing, the objections and hazard just exposed in connection with the existing line of obstructions and neighboring river batteries would have been entirely obviated, while by the construction of two strong field works on the river bluff in advance of Fort Boggs, to secure a plunging fire on and take the enemy's fleet in the rear should an attempt be made to remove the obstructions, the line of our works could at any time be evacuated without endangering the safety of the city, for in that case they would only be required to perform their legiti-