The Army of the Potomac has been crossing Harper's Ferry. He describes an engagement with Rebels, as well as the surrounding land and supplies, including local horses. He has suffered from jaundice. "There was a gap in the Blue Ridge here which was necessary to seize…Our troops had not been there more than an hour or two before ten or fifteen thousand Rebs were seen marching up to take possession. They were allowed to approach within easy cannon range, when our batteries pitched in and scattered them...In the mean time the army is advancing towards the country south-east of Winchester, where there will probably be a great battle unless the rebs run away...Gen McLellan is in the adjoining room with Fitz-John Porter. He is in high spirits at having got possession of the Mountain Pass yesterday without bloodshed."