The following table exhibits the amount of siege artillery, with the corresponding dates, put into position preparatory to the explosion of the mine on the front of the Ninth Corps on July 30. The designations of the batteries refer to the official sketch of the line, prepared on September 13, 1864, by Major Michler, chief engineer, Army of the Potomac:

Date. Company. Commanding officer.

1864.

June 20 I, 1st Connecticut Captain Burton.......

Artillery.

24 D, 1st Connecticut Captain Brigham.......

Artillery.

24 I, 1st Connecticut Lieutenant Jackson.

Artillery.

25 D, 1st Connecticut Lieutenant Lincoln or

Artillery. Lieutenant Williams.

27 F, 1st Connecticut Captain Dow..........

Artillery

27 ........................ Major Trumbull........

30 B, 1st Connecticut Captain Brooker.......

Artillery.

July 6 ........................ ...do.................

6 A, 1st Connecticut Captain Gillett.......

Artillery.

8 G, 1st Connecticut Lieutenant Sergeant

Artillery.

9 .......do............... Lieutenant Andrews.

9 .......do............... Captain Osborne......

25 M, 1st Connecticut Captain Pratt.......

Artillery.

28 K, 4th New York Captain Gould......

Artillery.

28 C, 1st Connecticut Captain Pierce.....

Artillery.

28 A, 1st Connecticut Lieutenant Patterson..

Artillery.

29 H, 4th New York Captain Brown.........

Artillery

29 C, 4th New York Lieutenant McPherson.

Artillery

Date. Armament. Locality and remarks.

1864.

June 20 Three 30-pounder Battery 4

Parrotts

24 Four 30-pounder Parrotts Battery 1

24 Four 8-inch mortars... Battery 10

25 Five Coehorns......... Three to Battery 9, two

to battery near Fort

McGilvery.

27 Three 30-pounder Battery 5

Parrotts, four 8-inch

mortars.

27 ..................... To assume command of

batteries on line of

Eighteenth Corps.

30 Six 4 1/2-inch guns Battery 17

July 6 ...................... To assume command of

batteries on line of

Ninth and Fifth Corps.

6 Four 8-inch mortars... In front of Battery 14.

8 Two 8-inch mortars.... Near Battery 11.

9 Five Coehorns......... Near Battery 12.

9 One 13-inch mortar.... On railroad near Battery

3.

25 Six 13-inch mortar.... Fort Morton.

28 Six Coehorns.......... Near Battery 11.

28 Ten 10-inch mortars... Near Fort Rice.

28 Six 8-inch mortars.... Near Battery 20.

29 Six 4 1/2-inch guns... Fort Sedgwick.

29 Six Coehorns. In front of Battery 15.

Total, 81 pieces.

From the time of going into position until the explosion of the mine, the fire of most of these batteries was incessant, and their practice was all that could be desired.

On July 30 the mine on General Burnside's front was sprung at 4.45 a.m., and a heavy cannonade was instantly opened and continued until about 10.30 a.m., when it gradually ceased, the assault of the infantry having failed and the attack being discontinued. The part assigned to the artillery to keep down the fire of the enemy upon the flanks of the column of attack and to keep down the fire of the enemy upon the flanks of the column of attack and to keep back hi re-enforcements was successfully executed. This battle was probably the first in which spherical case from heavy mortars was used. The expedient of putting thirty 12-pounder canister-shot under the bursting charge of the 10-inch shells was of great utility, their steady fire keeping quiet the most dreaded flanking batteries of the enemy's line.