SEPTEMBER 15TH.—And, just as I expected, Mr. Benjamin is to be Mr. Walker’s successor. Col. Bledsoe is back again ; and it devolved on me to inform Major Tyler that the old chief of the bureau was now the new chief. Of course he resigned the seals of office with the grace and courtesy of which he is so capable. And then he informed me (in confidence) that the Secretary had resigned, and would be appointed a brigadier-general in the army of the Southwest; and that he would accompany him as his adjutant-general.