outside adjacent to the two fronts occupied, inclosing them by a substantial fence running from one salient to the other. Access to these buildings from the interior of the front could have only through one of the lower tier of embrasures, which would have to be enlarged by cutting out the sill to the depth of 10 or 12 inches. As it is of concrete I presume this might readily be done; the fence on each front would be about 100 yards long; two kitchens 20 by 50 feet would be require, and a hospital 100 by 25 feet, the whole, including bunks, costing from $2,000 to $3,000. It would not be advisable to occupy more than two fronts of the work, as a greater number of prisoners than 500 would be more than the ordinary garrison of the fort could securely guard. The supply of water at the fort is limited, but it would probably be sufficient for the proposed number of prisoners.

After visiting Fort Schuyler I consulted Colonel Delafield, Engineer Corps, who is in charge of the forts in New York Harbor, as to the propriety of using any of them as military prisoners. Assuming that the fort will not be immediately required for the defense of the harbor the chief objection which he suggested is the one I have already mentioned, viz, that is puts in the power of the prisoners to destroy or seriously injure the fort they occupy by fire. However remote this possibility may be it does exist, and it is a grave question whether such a risk should be taken if it is possible to avoid it.

I then visited Fort Columbus, on Governor's Island. The fort itself furnishes no room for prisoners, but in Castle Williams, and outwork of two tiers of guns in casemates and one -inch guns in barbette, the third floor of which consists of arched rooms for the garrison, some 500 prisoners may be accommodated. The floors are of wood, and though they may be set on fire there is less risk of it than at Fort Schuyler, as the prisoners occupy separate rooms. This castle is used at times for prisoners of war, but it is generally devoted to deserters from our Army, and I recommend that it continue to be so used and for prisoners under sentence.

There are at this more prisoners at Fort Lafayette than can be accommodated there without interfering with the work of remounting the batteries with heavier guns, as has been ordered.

For some time past there has been a camp on Riker's Island, which is in the East River between the city and Fort Schuyler; but the camp is about being transferred to another island, and if offers and excellent location for a place of confinement for prisoners of a special character, which at this time is much needed. We have officers under special charges, blockade runners, piratical cases, political prisoners, and women, all of whom should be kept separate from ordinary prisoners of war and from each other, and I respectfully recommend that a suitable prison be erected on this island of sufficient extent to receive 1,000 prisoners and so arranged as to be capable of enlargement if necessary. There are but two or three buildings on the island, which are now used as store-house. I am informed by Major Van. Vliet that it costs about $25 per man to erect barracks for soldiers in the vicinity of New York. A prison may, therefore, be escaped to cost $25,000 to $30,000. Water is scarce upon the island, but if it cannot be supplied by cisterns receiving the water from the roofs it may be furnished by a water-boat.

On Saturday night I proceeded to Boston, but on Sunday I was only able to make arrangements to visit Fort Warren on Monday. Early on Monday morning I proceeded to the fort and examined its accommodations for prisoners, of whom there are now about 120 there, more