outwork to Fort Baker, having a pretty good view of approaches on either side of the ridge, not seen from Fort Baker.

Fort Baker was designed on correct principles as a strong point on the ridge. Its site is the only one between Forts Meigs and Stanton admitting considerable dimensions. It is a strong and well-armed fort. A ravine near and parallel to its front requires a battery or block-house to guard it. The steep slopes behind it may be well defended by rifle-pits. Additional bomb-proofs are necessary for the garrison. The magazine entrances at this and several other works of this group should be screened by traverses.

Fort Wagner is a battery intended to sweep the valley through which the road leads up the heights.

Fort Ricketts is a battery intended to see the ravine in front of Fort Stanton, which it does but imperfectly.

Fort Stanton occupies the nearest point of the ridge to the arsenal and navy-yard, and overlooks, Washington, the Potomac, and Eastern Branch. It is a work of considerable dimensions, well built, and tolerably well armed. Casemates for reversed fires are recommended in northwest and southwest counterscarp angles, and platforms for two or three rifled guns on the east front. The deep ravine which flanks this work on two sides requires some additional precaution, and further study of it is recommended.

Fort Snyder may be regarded as an outwork to Fort Stanton, guarding the head of one branch of the ravine just mentioned. Except additional platforms for field guns,and a ditch in front of the gorge stockade, and block-house, nothing further seems necessary.

Fort Carroll.- South of the ravine already spoken of, the character of the ridge between, Oxen Creek, and the Eastern Branch changes. Instead of a narrow ridge, it expands, at a level 60 or 70 feet lower, into a plateau of considerable width. At Fort Carroll this plateau narrows so as to afford a view of both slopes. A spur toward Oxen Creek gives a fine view of its valley opposite Fort Snyder to opposite Fort Greble. This point is occupied by a battery, inclosed at gorge by a stockade. The fort itself is large and well built. The Commission recommended bomb-proofs for garrisons and provisions, and additional platforms for field guns, and counterscarp casemates for flanking the ditches.

Fort Greble occupies the extremity of the plateau. It is a large and powerful work, well provided with magazines and bomb-proofs. The Commission recommend the construction of flanking casemates in counterscarp and additional platforms for field guns.

In relation to this group of works, the Commission express the opinion that an enemy will not attempt to enter Washington from this direction, and that we cannot (as a general rule) expect to be able to meet him with a line of troops. What is to be prevented is the seizure of these heights for the purpose of establishing batteries to destroy the navy-yard and arsenal. For this purpose the works should be self sustaining,or relying only upon such aid as a small movable body of troops can furnish, and upon succor, which may be thrown over the Branch after an attack is developed. It is under this view that the considerable increase of strength to Fort Meigs is deemed necessary, and other recommendations are made.

Rifle-pits. - A line of rifle-pits commences at Fort Lyon and is continued to the Potomac near Fort De Kalb, interrupted only in the bottoms of Hunting Creek and Four-Mile Run (where obstructions replace it), or occasionally by ground so broken that continuity is not necessary. In this line are frequent emplacements for field guns, openings for