intended to contain but 800. It now contains nearly 1,000 more. I append a table of the measurements of the various parts of the prison, with a calculation of the number of cubic feet and inches of air allowed to each prisoner. These measurements and calculations were made by Acting Assistant Surgeon Williams at my request, and I presume them to be correct, though I have had no time to verify them.

A. M. CLARK,

Surgeon and Acting Medical Inspector of Prisoners of War.

[Sub-inclosure.]

Admeasurement of quarters in Alton Military Prison January 10, 1864.

Width. Length. Height.

Quarters. Feet. Inches Feet. Inche Feet. Inche

. s. s.

Room Numbers 1 a. 7 20 3 4 4 25 6 6 9 9 3 3

.

Room Numbers 2. . 13 . . 49 9 9 4

Room Numbers 3. . 13 . . 49 9 9 4

Room Numbers 4. . 12 4 46 2 8 3

Room Numbers 5. . 12 6 27 8 9 5

Penitentiary: b

Sides

East side. . 8 10 153 9 33 4

West side. . 8 10 153 9 33 4

Ends

1. . 9 1 20 2 33 4

2. . 9 1 20 2 33 4

Cells, old (88) 3 10 7 . . 7 3

c. .

Cells, new (168) 4 1 7 7 7 3

c. .

Cells, doors. . 1 8 1 9 5 10

Little house, 14 2 19 10 9 6

above. .

Little house, 11 3 18 9 7 2

below. .

Old dead-house. . 15 6 24 . . 12 8

Old stable, 29 9 49 4 12 . .

above. .

Old stable, 29 9 49 4 9 5

below. .

Rock building, 46 . . 46 8 11 2

above. .

Rock building, 46 . . 97 . . 13 4

below. .

Quarters of 50 . . 103 . . 20 6

Federal

prisoners. .

Quarters of 50 . . 36 . . 17 . .

civilian

prisoners. .

Average allowance air to each man.

Total number-

Quarters. Cubic Cubic Number Feet Inches

feet. inches of . .

. inmates

.

Room Numbers 1 a. 5,097 1,560 23 265 261

.

Room Numbers 2. . 6,037 792 42 143 1,294

Room Numbers 3. . 6,037 792 36 167 1,222

Room Numbers 4. . 4,651 280 28 166 195

Room Numbers 5. . 3,256 1,032 32 101 1,325

Penitentiary: b

Sides:

East side. .

West side. .
102,756 832

Ends:

1. .

2. .

Cells, old (88) 700 204 1,119

c. .

Cells, new (168) 40,497 72

c. .

Cells, doors. .

Little house, 2,669 408 13 205 486

above. .

Little house, 1,511 1,242 13 116 494

below. .

Old dead-house. . 4,712 . . 20 235 1,036

Old stable, 17,082 1,188 120 142 614

above. .

Old stable, 13,821 1,184 80 172 1,332

below. .

Rock building, 23,971 192 200 119 1,478

above. .

Rock building, 59,493 576 275 216 586

below. .

Quarters of 105,575 . . 197 535 1,578

Federal

prisoners. .

Quarters of 30,600 . . 57 536 1,455

civilian

prisoners. .

427,770 1,510 1,836 232 1,700

a Measured in two parts, being partially by a partition.

b 33 feet 4 inches is the mean height.

c Main body of prison.

HEADQUARTERS EIGHTEENTH ARMY CORPS,
DEPARTMENT OF VIRGINIA AND NORTH CAROLINA,

Fort Monroe, February 19, 1864.

Honorable E. M. STANTON, Secretary of War:

SIR: Upon the matter of the declaration of exchange of prisoners I have the honor to report that following what I believed to be the ordinary routine of the business of exchange, and in order that the equivalent of our men might be put into the filed to meet those received from us by the Confederates, I made the declaration of exchange.

It is "in ipsissimis verbis" so far as applicable with the other declarations of exchange heretofore made, copies of some of which I hereunto annex in proof of this assertion.

This declaration, it will be observed, only affects those men actually delivered at City Point.

The Confederate commissioner, acting, as I believe, under the exact provisions of the cartel, has declared exchanged those who have been