The scenes ensuing upon the arrival of an army corps at its camping ground for a night, after a day's march, are very lively, often amusing, and sometimes present picturesque effects. Where the country traversed by the army is known to the commander, he is able to designate the nightly camps of the different corps with precision; if, on account of ignorance of the country, this cannot be done, places are approximately indicated upon the information given by maps or extracted from the inhabitants, or procured by reconnoitring parties. Usually, however, the commander possesses considerable topographical information, procured by his officers in the advance with the cavalry and light troops, so that he can fix the nightly camps in such a manner that the various corps shall all be upon the same line, and lie within supporting distances. The vicinity of streams is invariably selected for a camp, if other circumstances permit. When a corps arrives within a mile or two of its destination, the commander sends forward some of his staff officers (accompanied by a cavalry guard, if the country is suspicious), and these officers select the different localities for the camps of the divisions, of the artillery, the cavalry, and the trains, care being taken to give all equal facilities for wood and water, and at the same time to take advantage of the features of the country for military purposes, such as the guarding of roads in all directions, the establishment of the picket line, &c. The leading division arrives perhaps at 5 P.M., and its commander is shown to the locality assigned him. He immediately distributes the ground to the brigades, and the troops, as fast as they arrive, filing into the designated spots, occupy but a few moments in the necessary formalities by which disorder is prevented; then each man quickly spreads his little tent upon the place which in the military order belongs to him, a general din of cheerful voices arises, a unanimous rush is made to the water, cooking fires are kindled in all directions, and in ten minutes a scene of (it may be) utter desolation becomes full of life and activity. For a couple of hours the columns continue to file in, until all the hillsides are covered with tents. Then, far into the night, is heard the braying of mules, the shouts of drivers, and the rattling of wheels, as the heavy wagon trains toil to the place of rest. All through the evening prevails that peculiar, cheerful din of a camp, as peculiar and characteristic as the roar of a great city; gradually the noises decline, the bugles and drums sound the tattoo, the fires grow dim, and the vast mass of hardy, resolute humanity is asleep--all except the two or three score of sick and dying men, wasted by fever, who have been jolted all day over the rough roads in the ambulances, and now groan and writhe in delirium upon their narrow stretchers in the camp hospitals.