I am writing this, nearly sundown, watching a cavalry company (acting Signal service,) just come in through a shower, making their night's camp ready on some broad, vacant ground, a sort of hill, in full view opposite my window. There are the men in their yellow-striped jackets. All are dismounted; the freed horses stand with drooping heads and wet sides; they are to be led off presently in groups, to water. The little wall-tents and shelter tents spring up quickly. I see the fires already blazing, and pots and kettles over them. Some among the men are driving in tent-poles, wielding their axes with strong, slow blows. I see great huddles of horses, bundles of hay, groups of men (some with unbuckled sabres yet on their sides,) a few officers, piles of wood, the flames of the fires, saddles, harness, &c. The smoke streams upward, additional men arrive and dismount--some drive in stakes, and tie their horses to them; some go with buckets for water, some are chopping wood, and so on. _July 6th_.--A steady rain, dark and thick and warm. A train of six-mule wagons has just pass'd bearing pontoons, great square-end flatboats, and the heavy planking for overlaying them. We hear that the Potomac above here is flooded, and are wondering whether Lee will be able to get back across again, or whether Meade will indeed break him to pieces. The cavalry camp on the hill is a ceaseless field of observation for me. This forenoon there stand the horses, tether'd together, dripping, steaming, chewing their hay. The men emerge from their tents, dripping also. The fires are half quench'd. _July 10th_.--Still the camp opposite--perhaps fifty or sixty tents. Some of the men are cleaning their sabres (pleasant to-day,) some brushing boots, some laying off, reading, writing--some cooking, some sleeping. On long temporary cross-sticks back of the tents are cavalry accoutrements--blankets and overcoats are hung out to air--there are the squads of horses tether'd, feeding, continually stamping and whisking their tails to keep off flies. I sit long in my third story window and look at the scene--a hundred little things going on--peculiar objects connected with the camp that could not be described, any one of them justly, without much minute drawing and coloring in words. A NEW YORK SOLDIER