_July 20_ (Tuesday). We again encamped on Bitter Creek, after a march of fifteen miles. There is no improvement in the aspect of the country, although there was not so much labor, required in the construction of the road, the country being for the most part level or rolling. A great deal of poor coal is scattered over the ground, which is covered, throughout the latter six or eight miles of our march with a complete bed of these fragments, mixed with basaltic trap and a dark conglomerate containing an immense number of small shells. To-day we were compelled to mourn the loss of one of our companions, who, afflicted with apoplexy, was left, a few days ago, with the Regiment. He died at 8 p.m. and was buried in his uniform, the Sixth Regiment escorting the body to its wild and lonely resting place, with the customary military honors. I, myself, carved the board erected at his head: IN MEMORY OF WM. G. SLAYTER Of Co. "A," U.S. Engineers, Died July 19, 1858, Aged 27 years. His was a frank and genial nature, and his many good qualities and cheerful disposition had established him as a universal favorite among his comrades. His death threw a gloom over our usually cheerful and buoyant spirits. This evening the camp was still. The customary song was not heard--no hearty peals of laughter rang out to disturb the solemn silence. _July 21_ (Wednesday). We made but a short march to-day, the country over which we passed being unfavorable for the construction of the road. We encountered many deep gullies, which detained us a considerable time. Nine miles' marching brought us to another camp on Bitter Creek. About three miles from yesterday's camp we discovered the road that Captain Marcy made a few weeks ago. It was on the opposite side of the creek, however, and we could not form a junction with it, owing to the difficulty of crossing the creek.