We are told, as we perform this duty, that it is not very unlike the picketing that will be required of us if we are ever permitted to take the field which confronts the enemy. Indeed, this is picketing on a small scale. And our enthusiasm in this branch of our work increases, as we are almost daily in receipt of accounts of attacks on our pickets along the line of the Baltimore and Ohio Railroad and the Cumberland Canal. It appears that a certain Colonel Turner Ashby, with a force of cavaliers (?) acting as guerillas, singly and in squads, is nightly endeavoring to sever our telegraph wires, to burn our railroad-bridges, and to destroy the canal, or fire at our men on the passing boats; and not unfrequently we read of skirmishes in which several of our pickets have been either captured, wounded, or killed. Of course, we expect before long to face Mr. Ashby and his confederates, and we are preparing ourselves for it. MOUNTED DRILL. But this we do specially in the drill. Recently the balance of our men were gladdened with a full supply of horses. Mounted drill is now the general order, and nearly all our time not otherwise occupied is devoted to this exercise. At first we had some exciting times with our young and untrained horses. One of our men received a kick from his horse which proved fatal to his life. Several of our wildest and seemingly incorrigible ones we have been compelled to run up the steepest hills in the vicinity, under the wholesome discipline of sharp spurs, until the evil has been sweated out of them. We find, however, that the trouble is not only with the horses, but frequently with the men, many of whom have never bridled a horse nor touched a saddle. And then, too, these curbed bits in the mouths of animals that had been trained with the common bridle, produced a most rebellious temper, causing many of them to rear up in the air as though they had suddenly been transformed into monstrous kangaroos, while the riders showed signs of having taken lessons in somersets. Some of the scenes are more than ludicrous. Horses and men are acting very awkwardly, also, with the guiding of the animal by the rein against the neck, and not by the bit, as we were accustomed to do at home. We do not wonder much that the chivalrous Black Horse gentry have expressed their contempt of Northern "mudsills and greasy mechanics," and have made their brags that we could never match them. But then it is said that these Southrons were born in a saddle, and were always trained in horsemanship. They generally perform their pleasure excursions, go on their business journeys, and even to church, on horseback. They were therefore prepared for the cavalry service, before we had so much as _thought_ of it. But let them beware of what they think or say, for _we can learn_, and it does frequently occur that somewhere in the experience of contending parties, "the first is last, and the last first."