Pemberton is a strong work, and has an armament of twenty guns of various calibers. There are two batteries on the Ashley River to defend it and the entrance into Dill's Creek and the Wappoo. For want of guns they are still unprovided with their armament, except the one of Lawton's, which has four guns (32-pounders) of little use.

September 18.-Lieutenant this day, accompanied by the same officers as on the 17th instant, Forts Moultrie and Sumter, which were found to be in fine order and condition, considering the repairs in progress at the latter. The armament of the first consists of thirty-eight guns, of various calibers from 24-pounders to 8-inch columbiads, and the garrison of about 300 effective men. The armament of the second work consists of seventy-nine guns, of various calibers from 32-pounders to 10-inch columbiads and seven 10-inch mortars, and the garrison of about 352 effective men. The barracks in the latter work are being reduced in height to protect them from the enemy's shots. The small steam engine for making fresh water is in rather an exposed position. It ought to be removed to a safer place or be properly protected. Battery Beauregard, across Sullivan's Island, in advance of Fort Moultrie, to defend the approach from the east, is armed with five guns.

The work at the eastern extremity of the island, to defend the interior approach by water to the rear and west of Long Island, is a redoubt, armed with eight guns, two 32-pounders, the rest small guns.

I am informed by Major-General Pemberton that all the above works are sufficiently garrisoned. My conclusion is, that when the above works contemplated for the defense of this habor, especially the obstructions and gunboats, are completed and those works are properly armed with the heaviest guns, the enemy's vessels and gunboats will find it very difficult, if not next to impossible, to penetrate far enough to injure or take Charleston. Until then the city will not be properly protected.

September 19.-I inspected this day, with the same officers, the works at Secessionville, which are irregular and but poorly constructed. A force of about 200 men is still at work upon them, increasing and strengthening them. The position is naturally a strong one, being surrounded with low marshes and a wide creek, except on one side, where there is a very narrow strip of level ground, along which the Abolitionists made their attack, which amounted to a surprise, and yet they were defeated by one-fifth their number. I do not, however, see the necessity or advantage of holding in force this advanced position. A strong picket would be sufficient. The armament of this work consists of two 8-inch naval guns, one 18-pounder howitzer, six 32-pounders, one 32-pounder rifle, two 24-pounder rifles, and two 10-inch mortars.

September 20.-I left this day at 9.30 a.m. for Savannah on a tour of inspection with General Pemberton and Colonel Gonzales. Stopped at Rantowles Station to inspect works there-an open battery with four guns (two 24-pounders and two 12-pounders); a strong and good position, commanding roads from Savannah and Church Flats, on Stono, 3 miles off, where there is also a battery of three guns (two 32-pounders and one rifle 12-pounder) to command an obstruction and prevent a landing from John's Island and the passage by water up Church Flats, in which case troops at Adams Run 9 or 10 miles off, a central and healthy point, would have to support that battery or fall back on the one at Rantowles. The right flank of the latter should be extended, or a detached redean constructed toward the prairie or marshes in the direction of Wallace's-where there is also a battery of two guns (one 32-pounder and one rifled 6-pounder), occupying a strong isolated position-to flank battery at the station and two bridges across Rantowles