The plaintiff’s indorsement of his bill of lading had no validity, because he neglected to sign it. In consequence of this error on his part, Hooper Chase would not have obtained any title to the flour which he had agreed to forward, or any control over it. He had paid the draft to the defendants before he discovered the error; and when he discovered it, he had a right to demand and recover of the defendants the money he paid under a mistake of the facts. Jefts v. York, 10 Cush. 392; S. C. 12 Cush. 196. The plaintiff cannot with propriety urge that Chase was guilty of negligence in not discovering the error before he paid the money to the defendants ; for it was merely a failure to discover an error which the plaintiff had made. But if he was guilty of negligence, that fact would be immaterial. Appleton Bank v. McGilvray, 4 Gray, 522. The defendants, being bound to repay the money after the demand upon them, properly did so without suit, and are not liable to the plaintiff. ' Judgment for the defendants.