the arrangement of the lower parapets on the western front for placing two guns in embrasure. The accompanying drawing explains this complex work.

Casino Hill is half a mile distant from Fort Negley and one-third mile from Morton and is ten feet higher than this last fort. General Morton placed on this hill a single-cased block-house in the form of a cross, relying upon the combined fire of Morton and Negley to drive an enemy from the position should he attempt to build batteries there. Had Fort Morton been finished of the magnitude originally intended, its powerful armament might have accomplished that object by deluging the hill by its fire. I designed for this position a simple battery, with a deep ditch and eight-foot rock scarps. The two faces were directed upon Morton and Negley, so as to expose the hill to the fire of these forts. The forge line, simply a stockade closing on the block-house, leaves the interior open to fire from the works in the rear, so that no enemy could hold the battery, should he succeed in carrying it. Lack of men and the urgent necessity for forwarding more exposed points on the defensive line prevented the commencement of this battery. The hill is limestone rock with scarcely any soil, and steep on the line of approach.

Fort Morton.-This work had made some progress, according to the original plans, when Colonel Merrill (captain, Engineer Corps), foreseeing that it would never be finished, directed its abandonment and the substitution therefor of a polygonal redoubt, with guns en barbette and an interior block-house. When I assumes general direction of the Defenses of Nashville this fort was not half finished. I modified it slightly by increasing the number of guns and placing them in embrasure, diminishing the parapets unnecessarily thick, introducing two service magazines, which would serve also as traverses, and reducing the block-house from 120 to 80 feet length. It was my intention also the build a glacis around the work, revest the scarps with dry stone, and put flanks in the redan, so as to sweep the ditches of the fronts of attack; this has in part been done. The accompanying sketch shows these arrangements. The rocky character of the site of Fort Morton, its position on a high hill, the necessity for blasting the terre-plein and for the magazines, and for hauling earth from a much lower level, and the large keep have made this work expensive and retarded its progress. Fort Morton is nearly finished.

Fort Houston (now called Fort Dan McCook).-More labor has been expended on this fort than would have been required to build a large bastion work. In November, 1864, it was in a very unfinished condition. It progressed very rapidly for the period of three weeks, by the and of a large number of workmen, mostly from the quartermaster's department. It was made ready for twenty-six guns at the time of the battles of Nashville, though the polygons were not inclosed. A small force has been employed upon Fort Houston since December last. Nearly all the gabion embrasures have been constructed, and entrances walled, and the works inclosed. Much labor is required to finish it. Its dimensions are so great that a small number of workmen make slow progress upon it. When completed it will mount thirty-five guns for direct fire and ten flanking guns. The original design was very costly, involving independent scarp walls, an immense traverse, and bomb-proof store-houses. All these structures have been omitted in the modified plans. The north polygon, not being inclosed, was reduced in size, to avoid heavy embankments, and the reference of the interior crest dropped. The accompanying sketch will show the