Pine poles cut on Folly Island, cord wood found near the first parallel, old lumber from the Beacon House, and sand-bags, constituted the material employed int he construction of these shelters.

The rectangular transverse frame shown in Figs. 28 and 29 is the same as the longitudinal frame used in the narrow shelter shown in Figs. 30 and 31. The material for these frames was prepared at the engineer depot, and put together on the ground with 6-inch spikes. Three hundred and ten linear yards of wide and narrow splinter-proof shelter were built in advance of the first parallel, capable of protecting about 1,000 men.

The surgery int he second parallel was 32 feet long, 10 feet wide, and 5 1/2 feet high, and made bomb-proof by covering it with 7 feet of sand. Its frames were proportionately strong to bear this load.

T. B. BROOKS,

Major, and Aide-de-Camp.

Numbers 6. Report of Lieutenant Peter S. Michie, U. S. Corps of Engineers, Assistant Engineer.

ENGINEER OFFICE, NORTHERN DIST., DEPT. OF THE SOUTH,

Folly Island, February 1, 1863.

GENERAL: In compliance with your request, "that I should send in, as soon as possible, a detailed report of my engineering operations in this department previous to the 7th of September, 1863," I have the honor to submit the following:

I reported for duty at headquarters Department of the South, Hilton Head, S. C., on the 29th of June, 1863, and was ordered to report to C. R. Suter, first lieutenant U. S. Engineers, whom I relieved on the 1st of July, 1863, of the charge of the offensive batteries under construction on the north end of Folly Island, S. C. At this time the sites of all the batteries had been selected (excepting that of a small barbette battery of two Wiard guns, which was established, on the night of the 9th of July, between the right and left wings of the first line), and the interior revetments of sand-bags completed.

The immense supervision of the work was under the charge of Lieutenant Wilson, Fifth U. S. Artillery, and Lieutenant McGuire, New York Volunteer Engineers, both capable and efficient officers. The work that remained unfinished, and which was completed on the night of the 9th of July, was principally the clearing out and rivetting the embrasures, laying platforms for some of the mortars, building surgery and splinter-proofs, constructing a new road from the first to the second line, and, on the last night, cutting down the trees and brush which masked the batteries from the enemy.

So complete were the orders and arrangements of General Vogdes, that, notwithstanding large fatigue details of from 300 to 1,000 men were engaged in erecting and arming batteries mounting fifty guns* only a few hundred yards distant from a watchful enemy, yet not the slightest thing occurred to awaken their suspicions.

During the action of the 10th of July, I remained in the batteries, in charge of the engineer party, and directed the necessary repairs of embrasures, &c.

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*Forty-seven guns.

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