An attempt to pass the rebel batteries at Vicksburg, was made by the Union rams Lancaster and Switzerland, on the 25th of March, without success. As soon as they came within range, the rebels opened a tremendous fire. The Lancaster was struck thirty times. Her entire bow was shot away, causing her to sink immediately. All the crew except two escaped. The Switzerland was disabled by a 64-pound ball penetrating the steam-drum. She floated down, the batteries still firing, and striking her repeatedly, until finally the Albatross ran alongside and towed her to the lower mouth of the canal. An expedition proceeded down the Coldwater, on the 2nd of April, consisting of a portion of General Sherman’s and General McClernand’s corps, under General L. F. Ross, with eighteen transports and five small gunboats, and arrived at the mouth of the river without obstruction. They proceeded down the Tallahatchie, to its junction with the Yallobusha, which there forms the Yazoo, near which point is the village of Greenwood. On a peninsula near by, the rebels had erected a fortification. It consisted of a single line of breastworks facing westerly, composed of cotton bales and earth, and flanked on the right by a battery of three heavy guns fronting the river. Other field-pieces were in position on the works. On the right flank of the line, a defence or raft of logs had been constructed, to serve as a blockade of the river. Directly in front of the breastworks was a deep slough, extending across the peninsula, and admirably serving the purpose of a ditch. The slough was close to the base of the works at the upper end, but gradually receded from them at the lower, where it was several hundred yards distant. Beyond the slough there was an almost impenetrable canebrake, backed by an extensive forest. The reduction of this fort was an inevitable necessity, before the expedition could proceed further, and the gunboat Chillicothe, Lieutenant Foster, was sent forward on the morning of the 11th of April to reconnoitre. The vessel approached the fortification, and fired several shots, but was soon struck four times by heavy rifle shots.