October 13th.—Mr. Duncan, attended by myself and other Britishers, made an extensive excursion through the camps on horseback, and I led him from Arlington to Upton’s House, up by Munson’s Hill, to General Wadsworth’s quarters, where we lunched on camp fare and, from the observatory erected at the rear of the house in which he lives, had a fine view this bright, cold, clear autumn day, of the wonderful expanse of undulating forest lands, streaked by rows of tents, which at last concentrated into vast white patches in the distance, towards Alexandria. The country is desolate, but the camps are flourishing, and that is enough to satisfy most patriots bent upon the subjugation of their enemies.