STEAMER MAGNOLIA,

Camp opposite Vicksburg, February 1, 1863.

GENERAL: I have to acknowledge receipt of Department letter of January 23 and telegram of January 28. The canal was closed yesterday afternoon by a dam of corn-sacks, filled with earth, resting against a wooden framework. No difficulty was experienced. Leveling shows the difference of level of the water at the two ends of the canal to be 2. 62 feet. Another trial of the velocity yesterday gave three minutes for 422 feet, the same distance as mentioned in a previous letter to have been performed in two minutes. What causes the discrepancy I am unable to say. The river is still rising. Captain Jenney reports 6 inches rise in last twenty-four hours, as opposed to 5 inches in previous twenty-four hours. Captain Kossak (from Corinth) reported here for duty to-day. He says the works there should be completed within ten or twelve days if the men work well. He complains of want of energy and indifference on the part of the contraband. When the present works are completed, there will still remain two or more large reserve magazines to be constructed near the brick seminary. The map of Corinth (our works, the rebel works, and our approaches) is completed, and will shortly be sent to General Cullum through the Department. A trace copy will be retained here for reference.

I am, general, very respectfully, your obedient servant,

FREDERICK E. PRIME,

Captain of Engineers.

Brigadier General JOSEPH G. TOTTEN, Chief Engineer of the Army.

STEAMER MAGNOLIA,

Opposite Vicksburg, February 9, 1863.

GENERAL: I have the honor to report as follows with respect to operations in my charge at this point: The water is still rising at the rate of 2 1/2 inches per twenty-four hours for past two days. A dam has been erected at each point where the canal crosses the levee. The water in the intermediate space will be let out into the swamps and low gerunds as soon as the camps south of the railroad and WEST of the canal have been entirely removed, which, I trust, will be tomorrow. This will render it practicable to remove the stumps and trees now in the canal, and to widen and deepen the canal to the necessary dimensions. A frame is being sunk in the excavation for the new entrance. It has reached a depth of 6 feet below the surface, and stiff clay is the material now encountered. The water seeps in so that at present the excavation in the new entrance cannot be pushed deeper than about 4 feet on an average.

The well formed by the frame and sheet-piling is to be used for draining the canal, by large steam-pump ram-a steamer belonging to the Navy; one has an 11-inch discharge and the other 18-inch. But few soldiers are at present employed, on account of shifting camps, building roads, &c., and the delays which have prevented the canal from being emptied. Five hundred and FIFTY contrabands are now here and are employed on the new entrance of the canal. The work on the canal between the levees will most probably be assigned to the details furnished by the troops. With fair weather and strong working parties, there is a fair prospect of obtaining satisfactory results.

I am, general, very respectfully, your obedient servant,

FREDERICK E. PRIME

Captain of Engineers.

Brigadier General JOSEPH G. TOTTEN, Chief Engineer of the Army.