Chattanooga, Monday, May 15. Reveille sounded at 4 A. M. Harnessed and saddled up before feeding, ate an early breakfast and started out for brigade drill, five horse batteries on the ground by 6 A. M. Major Mendenhall drilled us for nearly two hours. The morning being cool, it passed off very pleasantly, and we returned to camp feeling better for the exercise. Remainder of the forenoon appeared long. Grazed in the afternoon and had an interesting game of chess with Ed. Hayes. No news, but many wild reports. Amongst the most exciting is that Jeff Davis is to pass through to-night.