hundred, and will attempt to land in launch-boats with 24 and 12 pounders, and it will probably be on the lower end of Morris Island, next the light-house. If so, we will have a fine rifle regiment to give them a cordial welcome from behind sand hills (that are natural fortifications), and two Dahlgren guns will be right on them, besides four 24-pounders in battery. I have four hundred fine Enfield rifles that have been practiced at nine hundred yards, and on that island, altogether, we have now one thousand nine hundred and fifty men, and are increasing it to-day.

There has just arrived on the bar a fine rifled cannon from Liverpool, of the latest maker (Blakely gun), an improvement upon Armstrong, of steel rolls or coils, with an elevation of seven and one-half degrees to a mile. It throws a shell or twelve-pound shot with the accuracy of a dueling-pistol, and only one and one-half pounds of powder. Such, they write me, is this gun, and I hope to have it in position to-night. We expect the attack about 6 o'clock in the morning, on account of the tide.

Very respectfully,

F. W. PICKENS.

[Inclosure Numbers 1.]

FORT SUMTER, S. C., April 8, 1861.

General JOSEPH G. TOTTEN,

Chief Engineer U. S. Army, Washington, D. C.:

GENERAL: The increased activity and vigilance of the investing force, as reported yesterday, still continues. Three large traverses are nearly completed on the front, from battery Numbers 3 to 5, on Morris Island, and traverses are also being erected in the interior of battery Numbers 5. Additions of sand bags are being made to the covering of the magazine, between Nos. 2 and 3, and to the left flank of Numbers 1, where I think they are constructing a service magazine.

I am busily at work constructing splinter-proof shelters on the terreplein. I obtain timber by taking the gun carriages to pieces, and form the covering of the 2-inch iron pieces for embrasures, as seen below. The plates are spiked on, so as to be securely retained in their places, even if struck by a shell, which I am confident it will turn.

Our supplies are entirely cut off from the city, and those on hand are very limited.

The besieging forces worked all day yesterday, whenever the intervals between the showers of rain would allow.

Very respectfully, your obedient servant,

J. G. FOSTER,

Captain, Engineers.

P. S. - I received yesterday a letter from the Secretary of War to Major Anderson, which, by mistake, had been enveloped to me. I handed it to Major Anderson without reading.

Respectfully, & c.,

J. G. FOSTER,

Captain, Engineers.

[Inclosure Numbers 2.]

Colonel L. THOMAS, Adjutant-General:

DEAR COLONEL: In another envelope I shall send a Numbers 96, which you will be pleased to destroy.

That God will preserve our beloved country, is the heart-felt prayer of your friend,

R. A.