Another simple statement will explain the chances of the enemy and the causes of many of our casualties. Our picket-lines are too much extended, covering too wide a territory to make them as strong as they should be. Only a brigade is doing the work of a division, and consequently the picket-posts are not sufficiently near each other. Thus, in the night, it requires no very great dexterity to creep through the bushes between the pickets unobserved, and, once within our lines, any amount of mischief may be done by the miscreants. The method indicated here is usually the one employed by these active guerillas, and it forms the chief stratagem of all their movements upon us. Their first important attack upon our pickets took place on or about the tenth of January. A small Federal picket was doing duty at Herndon Station, on the Loudon and Hampshire Railroad. Mosby determined to effect their capture. Led by a skilful guide, he dismounted his command some distance from the picket-lines. Then they all crept cautiously between the vedettes, until they reached the rear of the post, and from that direction advanced upon the unsuspecting boys, whose forms could be distinctly seen by the flaring light of their bivouac fire. While the pickets were thus a fine shot and mark for the enemy, the attacking force was concealed perfectly by the darkness of night and the shades of the thick pines. A pistol-shot from the guerillas was followed by a charge, when our boys were suddenly surrounded and captured. This attack and capture was followed by another similar enterprise a few nights afterwards at Cub Run, near the Little River Turnpike. The picket relief was captured by a charge made in their rear, and only the two vedettes made their escape. Later in the same night a similar assault was made upon our post at Frying-Pan Church. Not far from this church resides a Miss Laura Ratcliffe, a very active and cunning Rebel, who is known to our men, and is at least suspected of assisting Mosby not a little in his movements. The cavalry brigade doing picket duty at this point is composed of the First Virginia (many of whose men were raised in these parts), the First Vermont, the Fifth New York, and the Eighteenth Pennsylvania. The latter of these regiments has but recently been mustered into the service, is poorly drilled and worse equipped, and is by no means fitted to picket against so wily a foe as Mosby. Though great caution is exercised by Colonel Percy Wyndham, who is in command of the brigade, to arrange and change the alternation of the pickets, so that the regiments to picket at a given point may not be known beforehand; yet by means of Miss Ratcliffe and her rebellions sisterhood, Mosby is generally informed of the regiment doing duty, and his attacks are usually directed against the unskilled and unsuspecting.