was maintained until 1.30 a. m. of the 15th, at which time General Birney with his force joined General Hancock on the east side of Four-Mile Creek. During its continuance the lines was much used and afforded great advantages to the commanding general in communicating rapidly with General Birney regarding the operations of his force while separated for the time from the main body by Four-Mile Creek. On the 14th I also established a station of observation at the Potteries, overlooking the enemy's position on Spring Hill, and a road upon which he moved to re-enforce different parts of his lines. A number of important movements were observed and reported by myself and Lieutenant Neel. Lieutenant N., who occupied this station after the breaking up of his flag station, in addition to his duties of observation, directed with good effect the fire of one of our batteries stationed near him. A station of observation was also established just in rear of our picket-line near the New Market road, which overlooked the enemy's lines for a considerable distance. Lieutenant Holland was placed upon duty at this point, relieved occasionally by Captain Thickstun.
Upon the morning of the 15th a careful examination of the enemy's lines in the vicinity of Petersburg failed to disclose any further movements on their part. Some of their camps, broken up the previous day, appeared re-established in their old positions and reoccupied at daylight in the morning, showing that they had not removed many troops from our front. Everything remained quiet until 2.45 p. m., when a column of 1,500 infantry moved into the city from the southwest. This was the only change visible during the day. On the 16th the camps re-established the previous day were again broken up, and the force which occupied them apparently moved to the left, although they did not appear on the line of the Weldon railroad. Some of the troops in the fortifications in our front were relieved and moved in same direction, and others took their places, which did not materially weaken their front line. From the information derived from the reports of the different station on the morning of the 17th instant led me to believe and to report to the commanding general that the enemy's lines in our immediate front had been, to a great extent, weakened within the two or three days previous, which opinion was afterward confirmed. At about 1 a. m. on the 18th instant a heavy cannonading opened along our lines and continued for about and hour. At 4 a. m. the Fifth Corps commenced moving toward the Weldon railroad, and shortly afterward two brigades of the enemy moved from their works in the vicinity of the lead-works and passed southward along the Weldon railroad to meet General Warren's advance. A sharp engagement ensued, which at first was to our disadvantage, but we subsequently compelled the enemy to retire a short distance. At 4.30 p. m. a division of the enemy's infantry was reported by our stations as moving to the support of their force on the Weldon railroad. On the 19th stragglers were reported early in the morning as passing toward our left along the Weldon railroad, indicating that infantry in some force must have passed during the night. The strength of that force it was, of course, impossible to determine. In the afternoon, about 2 o'clock, the rear of a column of infantry (about two brigades) was observed moving toward our left, and at 5 p. m. a battalion of infantry, apparently the head of a much larger column, appeared on our left of the lead-works and halted. A heavy rain then set in and precluded the possibility of further operations on that day.
During the morning of the 20th no activity upon the part of the enemy was visible until 11 a. m., when a brigade of about 1,500 infantry moved out of Petersburg toward the left, and between that time and 4 p. m. about 2,500 or 3,000 more moved from their same place in the same direction. These troops moved apparently to the support of their forces on the Weldon railroad. During the previous night the Second