At length, after a month of toil and exposure almost unprecedented, after losing nearly one-fifth of our magnificent army by disease and death, our batteries were finished, the enormous siege guns were mounted, and the thirteen inch mortars in position. The army looked anxiously for the grand _finale_ of all these extensive preparations. Men had lost the enthusiasm which prevailed when we landed upon the Peninsula, and a smile was seldom seen; but a fixed and determined purpose to succeed still appeared in their faces. Now at length we were ready; and the countenances of the soldiers began to lighten up a little. But as the sun rose on the morning of the 4th of May, behold, the rebels had vanished, and with them our hopes of a brilliant victory! Unfortunately for our hopes of a great success at Yorktown, the rebel generals had shown themselves unwilling to afford us such an opportunity by waiting for us longer; and during the night of the 3d and 4th they had evacuated the place. They had gained a month of time for strengthening the defenses about Richmond, and for concentrating their forces there. Now they were ready to fall back without testing our magnificent works and huge guns, and lead us into the swamps of Chickahominy; where they hoped that the fever would complete the ghastly work already commenced at Yorktown. During the night of the evacuation, the roar of artillery exceeded anything that had been heard before. From one end of the line to the other the shells and shot poured into our camps, and the arches of fire that marked the courses of the shells, with flame spouting from the mouths of the guns, created a magnificent pyrotechnic display. But at daylight, orderlies flew from regiment to regiment with the startling intelligence that the beleaguered works were deserted, and with orders to occupy them at once. Smith's division hastened to cross over the dam, and we found ourselves in the strongholds that we had so long invested. As the Seventy-seventh regiment passed along one of the roads leading among the intrenchments, a sharp report like that of a pistol was heard at the feet of those in the center of the column, and directly under the colors. The men scattered, and a piece of old cloth was seen lying on the ground at the point from which the report emanated. Colonel McKean, who was very near, lifted the cloth with the point of his sword, and discovered a torpedo carefully buried in the ground, except a nipple which had been filled with fulminating powder, which was covered by the old cloth. The fuse only had exploded. Had the machine itself exploded, it must have destroyed many of our men, our colonel among them. Other regiments were not so fortunate as we were. Very many men were killed in the streets and intrenchments by these torpedoes, which the enemy had planted in the street at either end of the bridges, about springs, and near the deserted guns. They were concealed beneath the ground with