silent to-day, with the exception of Simkins, from which 37 mortar shells were fired at Battery Gregg, eliciting no reply. The mortars on the right of Battery Marion have not been fired within the past twenty-four hours for want of shells. Two men of the guard at Battery Pringle this morning deserted to the enemy between 2 and 4 a. m. They escaped, it is thought, in a boat used by Colonel Simonton's pickets, which was anchored off the battery. Three other men are missing, but it is supposed they are gone to the city. It is reported by Mr. J. J. Ryan, assistant superintendent of laborers on Sullivan's Island and Christ Church Parish, that no meat rations have been furnished the hands in his district on the 5th, 8th, 9th, and 13th instant. Pursuant to instructions form the commanding general arrangements were this day completed for holding Colquitt's brigade disposable as a movable column. The brigade is reported to be supplied fully with ammunition, canteens, &c., and is in condition for movement at any time.

Brigadier General R. E. Colston reports to-day as follows: On Tuesday, 12th instant, a communication was received form Captain Hanleiter, commanding Beaulieu Battery, to the effect that a non-commissioned officer had informed him of the existence of a plot among the garrison at Rose Dew Island (mouth of the Little Ogeechee River), the purpose of which was to abandon the post at Rose Dew, with arms, ammunition, &c.; to win over the troops at Beaulieu if possible; to advance toward Savannah, taking with them the Terrell Artillery, at White Bluff, whose adhesion was considered certain; also some State troops encamped on the Skidaway road, and to come to the camp of the Fifty-seventh Georgia, upon whom they seemed to rely as ready to join them. The whole to make their way to the interior of the country, their avowed purpose being to induce by their example as many of the troops as possible to imitate them, and by refusing to bar arms any longer "to put an end to the war." The plot was to be executed on last night. General Colston immediately sent Captain W. T. Taliaferro, his assistant adjutant-general, to Beaulieu and Rose Dew to investigate the matter. In the mean time an order was sent from district headquarters for the arrest of Private Coleman, Company F, Fifty-fourth Georgia, and he was sent on the the barracks at Savannah. From the result of investigations made by Major Hartridge, commanding at Rose Dew, and Captain Taliaferro, it became evident that this plot, which at first appeared so improbable, did really exist.

On yesterday General Colston ordered about 300 men from the First Georgia Regiment and the First Florida Battalion, under the command of Colonel Olmstead, First Georgia, to repair to the causeway connecting Rose Dew Island with the main land and cut off the communication between the two. Captain Guerard's battery of artillery was ordered to support him. One hundred and fifty men form the Sixty-third Georgia Regiment, under Major Allen, were ordered to report to Colonel Olmstead. These movements of troops were made ostensibly for the purpose of meeting some demonstrations of the enemy by way of the Ogeechee. No attempt of any kind was made on last night by the garrison at Rose Dew. The arrest of Coleman and the concentration of troops has evidently frustrated the design; but from the report of Sergeant Hinson to Captain Tanner (Jackson Guards, at Rose Dew) the attempt was not given up until late yesterday evening. Another non-commissioned