West Point, on the Hudson, fifty miles above New York, made strong by nature, and strengthened by art, was an object of covetous desire to Sir Henry Clinton. It was the key to the northern country and the route to Canada, and the strong link of co-operation between the patriots of the Eastern and Middle States. Arnold knew its value to both parties, and he resolved to make its betrayal the equivalent for personal honors and a large sum of money. When his determination was fixed, and his plans were arranged, his deportment was suddenly changed. Hitherto he had been sullen and indifferent; now his patriotism glowed with all the apparent ardor of his earlier career. Hitherto he had pleaded the bad state of his wounds as an excuse for inaction; now they healed rapidly. He was now anxious to join his old companions in arms, and to General Schuyler, Robert R. Livingston, and other influential men in Congress, he expressed his impatience to be in the camp or the field. Rejoiced at the change, and believing him sincere, they wrote letters to Washington commendatory of Arnold, and, in pursuance of his intimation, suggested his appointment to the command of West Point. At the same time Arnold visited the camp to pay his respects to the commander-in-chief, and expressed his desire to have a command, like that at West Point, for his wounds would not now allow him to perform active service on horseback in the field. Washington was surprised, but, unsuspicious of wrong, acceded to his request, and on the 3d of August, 1780, gave him written instructions. His command included West Point and its dependencies from Stony Point to Fishkill. [Illustration: ROBINSON'S HOUSE.] Upon a fertile plateau, high above the river, and at the foot of a range of lofty hills, nearly opposite West Point, was the confiscated country seat of Colonel Beverly Robinson, a spacious mansion for the times, and now a pleasant residence. There Arnold established his quarters, and elaborated his wicked scheme; and there he was joined by his wife and infant son, when his plans were ripe, and his treason almost consummated. It was a part of Washington's plan for the autumn campaign, to make an attack upon the city of New York, with the combined French and American forces, the former to approach by the way of Long Island, and the other by crossing Kingsbridge at the head of York, or Manhattan Island. Arnold communicated the details of this plan to Sir Henry Clinton, and proposed that when the assailants approached, a large British force should proceed up the Hudson to the Highlands in a flotilla under Admiral Rodney, when the traitor should surrender West Point and its dependencies, excusing himself with the plea of a weak garrison. The anticipated result was a retreat of Washington toward the Highlands to regain the fortress and save his ample stores and the probable capture of the French army.