detachments sufficient to guard the passes over that river and then moved with the main body on Lancaster, there is no reason why the enemy should not have been able to hold it in check on the line of Dick's River long enough to secure his line though Lancaster if he was determined to retreat.

An army on ordinary marches, continued for many days, will average about 2 miles an hour; but in a forced march for 20, and at least for 10 miles, it can average 3 miles an hour. If the rebel army had 60,000 men, with artillery, and 1,500 wagons for baggage, supplies, &c., it would in marching occupy 39 miles along the road in one column or 19 1 1/2 miles each in two columns, would clear its camp in six hours and a half, and arrive at Lancaster, 10 miles distant, in ten hours; or, if it continued on without stopping, would arrive at Crab Orchard, 20 miles distant, in fourteen hours.

It appears that the retreating army actually marched in three columns from its camp at Dick Robinson, the country along its route being open and practicable. From Lancaster it took two roads, the one to the left going by the way of Lowell and coming into the Cumberland Gap road at Big Hill, and the other going through Crab Orchard, Mount Vernon, and London. The latter is intersected at Crab Orchard, 20 miles from Danville, by the road from Danville through Stanford. The reasons which would render it injudicious to expose my communications and leave open a better line of retreat to the enemy, by anticipating his possible retreat through Lancaster, apply with greater force to Crab Orchard. If the rebel army would retreat without accepting battle, the topography of the country made it entirely possible for it to do so. Being once established on its line of retreat beyond any point where it could by any possibility be intercepted the rebel army made good its retreat, as other armies have done in this and other wars under less favorable circumstances.

There are few circumstances under which a disciplined and well-managed army can be forced to a general battle against its will, though the occasions are multiplied if the opposing army has a greatly superior force of good cavalry or is so greatly superior in strength that it can divide its force with reasonable prospects of success to each fraction. A disciplined army, moving on its line of communication, can always retreat more rapidly than it can be pursued. It meets or overtakes its supplies on the road, or finds them at temporary depots previously established, or it collects them from the country as much as possible on its line of march. The pursuing army, on the other hand, finds the country stripped; it has nothing in advance to rely on; it must carry everything along, with the hinderance of enormous trains, and the difficulties are increased with every day's march. The retreating army prepares a front of resistance more rapidly than the pursuer can prepare a front for attack. The strong positions are reconnoitered in advance, on which the requisite force forms as rapidly as on a drill ground; while the pursuer, ignorant of the ground and of the force that awaits him, must inform himself of both in order to develop a corresponding force, or else find the head of his column beaten back. In the mean time the main body of the retiring army has gained some hours' march; the rear guard watches the enemy's preparation, awaits his attack, and repulses it if is made injudiciously or with insufficient force, or else at dark