by signals were sent to a signal station (Numbers 2) placed on the saw-mill at General Heintzelman' headquarters, and were thence reported to headquarters station. Another station of observation (Numbers 3), in like manner repeating its messages through Station Numbers 2, at General Heintzelman's headquarters, was established on the Warwick road, in a piece of woods north of the cleared land in front of Lee's Mill, and near a small lunette, afterward taken by our forces. The post of observation small lunette, afterward taken by our forces. The post of observation of the officers here placed extended through a piece of woods southerly to the open ground in front of Wynn's Mill.

The position of these stations was easily discovered by the enemy. They were held through the siege with much risk to the officers ordered upon them. It was necessary to keep the officers there posted on duty for several days in succession, so that they might well know the localities of the enemy. The stations were hidden from the view of the rebel gunners. The danger was of injury from the fragments of the many shells thrown at the position during the thirty days they were occupied.

A signal flag was displayed in a tree, in sight of the enemy, at Station Numbers 3. The attempt to remove it was made hazardous by the enemy's musketry.

These competed the line of stations on the right. The dense woods covering the center and left of the army rendered signaling there impossible except from artificial stations. Soon after the siege had commenced the chief-signal officer was directed by the general commanding to cause signal towers to be erected and to be occupied as stations of observation and communication (if that was possible) along the front. It was hoped, also, that be observing from such points of view, and reporting the ranges of the shot and shell, the fire of guns and mortars soon to open on Yorktown might be accurately directed. These instructions were communicated to Lieutenant B. F. Fisher, acting signal officer, commanding the signal detachment on the left of the army, and Lieutenant N. Daniels, acting signal officer, commanding that with the center.

The sites for the towers on these portions of the line were at once selected by these officers. Large working parties reported to them, and the work of construction was commenced. On the right of the line, also, the positions for three towers were selected, and the timber for their construction was drawn from the woods and sharpened. Of these towers one (H) was to be on the shore of the bay, near Farinholt's house. A second (F) was to be on the high bank near the dam crossing Wormley's Creek. The third (G) on the elevated plain near the Clark house and near Camp Winfield Scott. None of these were, however, completed when the evacuation of Yorktown took place.

A station had been built close to Camp Winfield Scott, in an immense tree. This was sometimes used for purposes of observation. Other stations or perches were now made on trees close to the trenches and batteries of our approaches. From one of these, near Moore's house, and at a height of about 80 feet from the ground, could be had a distinct and close view of the enemy's works at Yorktown.

At the center Lieutenant Daniels, acting signal officer, caused to be raised a lofty structure of logs (E) near our picket line in front of Lee's Mill, and overlooking part of the enemy's works there placed. This tower was constantly occupied by a detail of signal officers as a station of observation, and whatever facts could thence be noted were reported to General Sumner. It was often visited by other officers, whose duties were aided by the observations here made. This stricture was in close range of the enemy's guns. Tough partially hidden by trees,