[Major Campbell] resumes command of Artillery Section Numbers 2, on James Island.]

Thirty vessels are reported inside the bar this morning, and six vessels as blockaders outside. All of same character and class as last reported.

At 10.50 p.m. Battery Cumming, with two guns, opened on the city, and fired 12 shells, one-half only of which exploded. As usual, Batteries Simkins, Cheves, Marion, Rutledge, and the Brooke gun battery returned the fire, and ceased as soon as the enemy closed, which he did at 11.40 p.m.

The number of shots fired from our works to-day is reported as follows: Battery Rutledge, 26 shells; Marion, 24 mortar shells; Brooke gun battery, 18 shells; Simkins, 18 shells, and Cheves, 14 shells.

Two steamers came up the Stono to-day, and one of them landed about 50 men at Legareville and at dark she was still lying at the village. The other had no troops, but returned after remaining only about thirty minutes.

The Marblehead is still lying in front of Legareville.

From the tenor of certain of the enemy's dispatches which have been intercepted, it is believed that there is a regular line of stations between Hilton Head and Morris Island, and that there is also a submarine cable connecting those two points. As orders and messages to intermediate points will probably be continued to be sent by signal, it is deemed important that our operators on John's Island by signal, it is deemed important that our operators on John's Island shall be over on the alert. Major Jenkins was accordingly directed to assume control of all members of the signal corps in his command.

December 20, 1863.-The enemy have remained silent since 4.40 last night, at which time they ceased shelling the city.

This morning the fleet off the harbor is composed of the usual number (six blockaders), while twenty-six vessels form the fleet inside the bar.

During the entire morning our batteries as well as those of the enemy, remained silent, but at 3.45 p.m. three guns at Battery Cumming opened on the city, and in thirty minutes threw 17 shells, only 5 of which failed to explode. Several buildings are said to have been struck, and one was set on fire, but was soon extinguished. No casualties are known to have occurred.

Shortly after the enemy commenced shelling the city, Batteries Simkins, Cheves, Marion, Rutledge, and the Brooke gun battery opened a steady fire with mortars, columbiad, and rifle shells, and ceased as soon as the guns on Cumming's Point ceased.

The effect of our fire was not ascertained, and no casualties are reported at any of our works.

The Federal steamer Marblehead is still near Legareville, and parties of the enemy can be seen in that village.

The enemy's fleet at Port Royal is composed of two steam frigates, two steam sloops of war, one steam cutter, two iron-clads, seven wooden gunboats, and ninety-four transports.

The following is the number of shots fired by our batteries during the day: Brooke gun battery, 30 mortar shells; Rutledge, 27 shells; Marion, 20 shells; Simkins, 4 columbiad, 3 rifle, and 11 mortar shells, and Cheves, 11 columbiad shells.

December 21, 1863.-There is no material change in either the number or character of the Federal fleet off the harbor this morning.