line of lunettes and redans around the city are about half finished, I should judge. These works are rather too close to each other, and unnecessarily strong in profile. There are about 1400 men (negroes) at work upon them. The obstructions—piling and cribwork filled in with stones and bricks—about one mile below Fort Jackson and its batteries, are nearly completed, requiring about ten or fifteen days longer to finish them. They will then obstruct very thoroughly, I think, the navigation of the river. They will, however, require to be watched and repaired constantly, owing to the effect of the current on the bottom between the cribs. The outer line of defences, consisting of detached works or batteries, at Thunderbolt and other points, armed with heavy guns, were not visited for want of time, but I am informed by General Pemberton that they are completed, well armed, and, with a proper garrison, could not be taken by the enemy, if well defended. By their advantageous position they cannot be turned. He places great reliance on them. An additional work at Coffee Bluff, on the Ogeechee, to be constructed, in the opinion of the Chief-Engineer of the Georgia District, Captain McCready. This must be looked into. Upon the whole, I consider Savannah thoroughly defended from a naval attack, and when its line of land defences will be completed, with a proper garrison of about 15,000 men, may be considered impregnable until the enemy shall bring against it an overwhelming force, which it is not probable they will ever attempt, as the result, if favorable, will not compensate them for the expense and trouble. September 24th.—I inspected this day, with Colonel Gonzales, the line of works on the Neck to defend the city of Charleston from land attack from the north. It is a continuous bastion line of strong profile and elaborately constructed, but badly located, I believe, not being well adapted to the ground. It is commanded to a certain extent by woods in front, and can be enfiladed and taken in reverse by gunboats on the Cooper and Ashley rivers, particularly from the last. No traverses have been constructed. They are absolutely required. Even then this line could hardly be held successfully against a fleet of gunboats in each of said rivers. The two batteries at the Half-moon Battery are not finished; they are intended for five and three guns each, to command the Cooper River and Town Creek. The distance to the former is too great. A much better position could be found, I think, on the opposite side of the river, at Hobcaw Bluffs, but obstructions would also be required. The profile of the parapet of those batteries is too great, especially of the first one. Adaptation of ‘means to an end’ has not always been consulted in the works around this city and Savannah. Much unnecessary work has been bestowed upon many of them.
Headquarters, Department S. C. and Ga., Charleston, S. C., Oct. 1st, 1862.I am instructed to furnish you with the following extract from a communication, dated 30th ult., from Dr. J. R. Cheves, in charge of outer obstructions:
Capt. W. H. Echols, Chief-Engineer: