Number of emplacements built for guns and mortars:

Against Fort Sumter on the left ............................. 1

Against Fort Sumter on the right ............................ 7

Against Fort Wagner previous to July 18 ..................... 17

Against Fort Wagner after July 18 ........................... 28

Defensive purposes .......................................... 36

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Total ....................................................... 89

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Number of bomb-proof service magazines ...................... 11

Number of splinter-proof service magazines .................. 7

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Total ....................................................... 18

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Number of defensive booms ................................... 3

This summary includes ten emplacements for ordnance and one bomb-proof service magazine built, but never used. It also embraces four emplacements for ordnance, one bomb-proof magazine, and 300 yards of sap, executed under the direction of Lieutenant P. S. Michie, U. S. Engineers, assistant engineer, Department of the South, who relieved me while sick, during the first week of September.

The siege work, extending through a period of fifty-five days, was chiefly done under cover of darkness, and under a fire of artillery and sharpshooters, more or less severe. In its execution, 23,500 soldiers' day's work, of six hours each, were expended. This number does not include the labor of preparing engineer material, only a small part of which was done under my direction.

Of this work, 8,000 days were employed on the defensive arrangements, 5,600 against Fort Sumter, and 9,900 against Fort Wagner.

The "day's work" of the soldier above mentioned is, as measured by the amount of work done, about one-fifth that which is ordinarily accomplished by a citizen laborer in civil constructions in a day of ten hours. The earth in which the men wrought was a fine quartz sand, containing a small amount of calcareous and vegetable matter.

Excepting the severe storm which occurred in the middle of August, the weather was favorable for work, the midsummer heat being greatly modified by cool sea breezes.

Considerable part of the siege material used was prepared and stored at the engineer depot at the south end of Morris Island. Sand-bags were by far the most expensive item of material employed, having been almost exclusively used for rivetting. About 46,000 were expended.

The accompanying journal records, with considerable minuteness, in accordance with your instructions, details of the siege operations. It embraces an account of methods used and progress made, officers and troops employed, dangers and difficulties encountered. It is compiled from the construction reports of superintending engineer officers, my own official communications, and reliable private diaries. In a few instances grammatical errors of documents herein incorporated, which had been hastily prepared during the active operations, have been corrected. In order conveniently to connect this record with others that may be submitted to you, I have noted several important facts relating to the siege not necessarily belonging to my report.

The following list embraces the most important events described