In this wretched plight we hear the summons to get ready to stand post. We go out upon our shivering horses, to sit in the saddle for two hours or more, facing the biting wind, and peering through the storm of sleet, snow, or rain, which unmercifully pelts us in its fury. But it were well for us if this was our worst enemy, and we consider ourselves happy if the guerilla does not creep through bushes impenetrable to the sight, to inflict his mortal blows. The two hours expire, relief comes, and the vedette returns to spend his four, six, or eight hours off post, as best he may. Once, at least, during the night, we are visited by the grand guard, which consists of the officer of the day, accompanied by others, whose duty it is to make a thorough, though usually swift, inspection of the picket line. Most of our time is spent in this duty. _March 29._--Considerable excitement prevailed among us to-day, as Colonel Bayard was dispatched with a detachment of his regiment to repulse a dastardly raid made by some of General J. E. B. Stuart's men, on the house of a Mrs. Tenant, a Union lady, residing near Difficult Run, about six miles from Chain Bridge. Colonel Bayard reached the place a few moments too late, and the raiders succeeded in taking Mrs. Tenant as a prisoner, and making off with their prey. For several weeks the main portion of our grand army has been sent by transports to the Peninsula, with the evident intention of moving upon Richmond by shorter land routes than by way of Manassas. This change in our plans of attack was probably known by the Rebels before they were matured at Washington, and we now understand why they so quietly evacuated their positions on our front. General McDowell remains in command of the defences of Washington, with a force sufficient, it is believed, to give safety to the Capital, and to harass the Rebels who continue before us. With the departure of General McClellan to the Peninsula, our picket lines were withdrawn to Annandale and Falls Church, within a few miles of the fortifications of Washington. THE ATMOSPHERE AND THE PEOPLE. _April 4._--The Harris Light and the First Pennsylvania Cavalry were recalled from the picket lines and sent out on a reconnoissance in force, with a division in command of General McDowell. Our march led us through Fairfax Court House and Centreville, near which we bivouacked for the night. Already, at this early spring time, a luxurious vegetable growth of green is beautifully carpeting the fields through which we pass and in which we halt. Flowers of great beauty and variety of hues and sweetness of perfume greet us on every hand. It would seem as though Nature were struggling to hide the desolations which war has made, and were weaving her chaplets of honor around the graves of our fallen brothers. And it really seems as though Destruction himself had contributed to this lavish growth. Thus,