Swash Channel, still open, 9 feet at low water, 14 feet at high watere. Main Ship Channel, obstructed, 13 feet at low water, 18 or 19 feet at high water.

Lawford's Channel, open, 7 feet at low water, 12 feet at high water.

TIME, PLACE, AND MANNER OF LANDING.

Our southern Atlantic beach is always rough on the flood tide whatever be the wind. I t is always rough on the ebb tide with any considerable inshore wind. But an ebb tide with no with, no wind, or a slight inshore wind, or any kind of offshore wind, secures a good landing. As these conditions are not fulfilled every day, or indeed every week, and as they cannot be predicted many hours ahead, it is necessary to have a rendezvous at hand-the nearer the better. 1 am disposed to think there should be two place: Bull's Bay for the Moultrie party, North Edisto for Sumter. The interior channels from each of these placed to Charleston Harbur may perhaps be used as auxiliary directions of attack. The inside channel from Bull's Bay enters Charleston Harbor at the point of Sullivan's Island, there-fourths of a mile from Fort Moultrie. It has of course a divide between each two inlets, and those divides being early or quite bare at low water, will pass boats or vessels drawing 4 or 5 feet thigh water. As the high water occurs on all these divides at the same time, it would generally be necessary oft vessels drawing 4 or 5 feet to use several tides in going through. Moreover, the channel passes occasionally near the Banks, or narrow islands which skirt the beach, and at these points a few field pieces would make the navigation difficult.

Enough has been said to show that we could not safety use this inside channel without first taking possession of the Banks. It is quite possible, however, that at the moment of landing on the beach of Sullivan's Island a few armed barges, having entered at Breach Inlet or Dewees' Inlet, might make a useful diversion in the reach.

LANDING ON SULLIVAN'S ISLAND.

The island generally is about one-fourth of a mile wide. Along the central part, about 1 1\2 miles from Fort Moultrie and 2 1\2 miles from Fort Sumter, along a reach more than one-half mile long at high water and during two or three hours after high water, gunboats of 10 feet draught can lie or maneuver within 300 yards of the beach. Under cover of their fire, and particularly of their cross-fire, good infantry, I think, could land and effect a footing. Once in possession a strip of the island extending back to the marsh, they could face right and left, and, with the continued aid of the gunboats, first take possession of the eastern end of the island, then advance upon Fort Moultrie within range of its guns, and commence the operations of a siege.

But the preliminary operation in this case in not without its difficulties and its doubts. If the enemy has notice of the attack and suspects the point of attack; if he has strong inclosed batteries at that point, with large bodies of infantry behind the sand hills supporting those batteries, the undertaking would seem to be too hazardous.

There is another mode of attack which ought to be undertaken at the same time. The success of either will be sufficient. I allude to an attack upon the eastern end of Sullivan's Island. Small craft, drawing not more than 3 feet, made proof, against musketry and field artillery, armed with musketry and boat howitzers, can be brought up in any