At the beginning of May, the additional transportation necessary for my advance beyond Flat-top had not arrived, but we did not wait for it. [Footnote: ._Id_., pt. iii. pp. 108, 112, 114, 127.] The regiments were ordered to leave tents behind, and to bivouac without shelter except such as they could make with "brush," for the expected shelter tents also were lacking. The whole distance from the head of navigation to the railroad at Newberne was one hundred and forty miles. Flat-top Mountain and Lewisburg were, respectively, about halfway on the two routes assigned to us. Some two thousand of the enemy's militia were holding the mountain passes in front of us, and a concentration of the regular Confederate troops was going on behind them. These last consisted of two brigades under General Henry Heth, as well as J. S. Williams's and Marshall's brigades, under General Humphrey Marshall, with the Eighth Virginia Cavalry. General Marshall appears to have been senior when the commands were united. Looking south from Flat-top Mountain we see the basin of the Blue-stone River, which flows northeastward into New River. This basin, with that of the Greenbrier on the other side of New River, forms the broadest stretch of cultivated land found between the mountain ranges, though the whole country is rough and broken even here. The crest of Flat-top Mountain curves southward around the headwaters of the Blue-stone, and joins the more regular ranges in Tazewell County. The straight ridge of East-River Mountain forms a barrier on the southern side of the basin, more than thirty miles away from the summit of Flat-top where Scammon's camp was placed on the road from Raleigh C. H. to Princeton, the county-seat of Mercer. The Narrows of New River were where that stream breaks through the mountain barrier I have described, and the road from Princeton to Giles C. H. passes through the defile. Only one other outlet from the basin goes southward, and that is where the road from Princeton to Wytheville passes through Rocky Gap, a gorge of the wildest character, some thirty miles south-westward from the Narrows. These passes were held by Confederate forces, whilst their cavalry, under Colonel W. H. Jenifer, occupied Princeton and presented a skirmishing resistance to our advance-guard.