HEADQUARTERS DEPARTMENT OF THE SOUTH, In the Field, Eng. Office, Folly Island, S. C., January 6, 1864.

CAPTAIN: I have the honor to report, for the information of the major-general commanding, that the line of signal towers from these headquarters to Hilton Head is now completed and in operation.

Beginning at Hilton Head, the line commences at the old headquarters building, from which it was proposed to telegraph to the signal tower erected at the junction of the roads between Beaufort and Saint Helena Village, and that leading to the Episcopal Church on Saint Helena Island, but the distance was found to be too great, and an intermediate station has been established at Jenkins' plantations, 8 1/4 miles from Hilton Head. This is merely a reading-room and platform. From Jenkins' to the tower, 6 1/2 miles, communication is made by military magnetic electric telegraph.

The tower upon Saint Helena Island is formed upon three very large hard pine trees, and over them, framing in successive sections up to a total height of 138 feet above the ground.

The next tower* is at Otter Island, 8 1/2 miles farther up the coast. The framework is two towers, one within the other, counterbraced. The total height is 142 feet above the ground. This tower is stockaded, and could, with a good garrison, hold out against an attack of the enemy for some considerable time. The stockade is flanked by tambours at two angles.

The next station is at Bay Point, Edisto Island, distant 5 miles from Otter Island. This is merely a temporary work 43 feet high, 16 feet square, and stands on a sand-hill about 18 feet above high water mark. It is surrounded by abatis, but is not otherwise fortified.

The next point is at Botany Bay Island, where there is a tower 138 feet high above the ground and 30 feet square at the base.

This tower,+ being at a very exposed point, has been well fortified by stockade, flanked on the angles by tambours and abatis outside. The entrance is by ladders over the abatis and stockade. These ladders are movable, and are to be drawn in at night, or in case of an attack. In the tower, 18 feet above the ground, there is a platform of timber, surrounded by a loop-holed wall of timber 4 feet high and 7 inches thick. This tower should be able to resist a strong attack.

RECAPITULATION.

Miles.

Hilton Head to Jenkins' ................................. 8 1/2

Jenkins' to Saint Helena ................................ 6 1/2

Saint Helena to Otter Island ............................ 8 1/2

Otter Island to Bay Point Island ........................ 5

Bay Point to Botany Bay ................................. 9 1/2

Botany Bay to Folly Island, south end ...................14

To department headquarters, Folly Island ................ 3 1/4

-------

Total ...................................................55 1/4

The towers at Botany Bay and south end of Folly Island are too far apart for service in bad weather, and an intermediate small station has been erected on Kiawah Island. Those on Folly Island do not form a part of the subject of this report.

The towers at Kiawah, Botany Bay, Bay Point, Otter Island, Saint Helena Island, and the station at Jenkins', were built by Lieutenant

---------------

*This tower is shown in the accompanying drawing, Plate XVI, p. 258.

+This tower is represented by Plate XVII, 259.

---------------