twenty-two. Two of these were placed behind traverses, with embrasures covered by blindages. The two external redoubts with the connecting parapets formed a re-entrant with the fronts of attack, and all the guns bore on our approaches. It will be seen, therefore, that our approaches were swept by the fire of at least forty-nine guns, nearly all of which were heavy, and many of them the most formidable guns known; besides that, two-thirds of the guns of the water batteries and known; besides that, two-thirds of the guns of the water batteries and all the guns of Gloucester bore on our right batteries, though under disadvantageous circumstances. Besides the above there were emplacements for four or five guns in the entrenchments running from Yorktown toward Fort Magruder. The guns on barbette carriages had not any protection, except in a few cases sand bags had been piled up. It is supposed that they awaited further indications as to the localities of our batteries before constructing merlons. For the guns on ship or siege carriages some arrangements had been made for protection by building up sodded merlons, or by sand bags and cotton bales, but as they were they would have been very inefficient against our fire.
The ravine behind which the left of the Yorktown fronts of attack was placed was not very difficult, and its head formed depressions in front of their left imperfectly seen by their fires, and from which access could be had to the ditches, but we could not be sure, of this fact before the evacuation. The enemy held, by means of a slight breastwork and rifle trenches, a position in advance of the heads of these ravines as far forward as the burned house. Our own rifle trenches were advanced to within 60 yards of the burned house-a point from which the day before the evacuation I made my last reconnaissance. Owing, however, to the fact that the enemy's riflemen were better concealed by shrubbery, &c., than our own, our men, who had just constructed their trench the night before, did not dare to show their heads or use their rifles, and I was unable to examine the grounds in front.
The ravines which head between the Yorktown fortifications and exterior works are deep and intricate. They were tolerably well seen, however, by the works which run westwardly from the Yorktown works, and which were too numerous and complicated to be traced on paper.
Fort Magruder, the first lunette on our left, appears to have been built at an early period, probably before the rear of Yorktown was inclosed, and to prevent the approach of an enemy who should attempt to pass the ravines. It had a moderately strong profile, but its gorge, a mere stockade, was taken in reverses by our Battery Numbers 13.
The Red Redoubt (square) farther to the left answered very well as a means of continuing the line and securing against assault by ordinary means, but its front was almost wholly occupied by barbettes for field or siege guns, and its interior was seen from our Battery Numbers 13. The exterior was seen from our Battery No 13. The exterior connection between this work was first a rifle trench, probably afterwards enlarged into a parapet, with external ditch and en emplacement for four guns in or near the small redan in the center.
Behind this they had constructed numerous epaulements, with connecting boyaux, not fully arranged for infantry fires, and mainly intended, probably, to protect their camps and reserves against the destructive effects of our artillery. From the Red Redoubt these trenches and epaulements ran to the woods and rivulet which forms a head with the Warwick, and continue almost without break to connect with the works at Wynn's Mill. This stream mentioned (whatever be its name, the term "Warwick," according to some, applying only to the tidal channel from the James River up as high as Lee's Mill) is