‘ … It is certain’, says Winfield, in writing of the liability for torts committed by servants of corporations, ‘that, whatever the law may be where the corporation has expressly authorised the commission of an ultra vires tort, no authority to the servant or agent to commit such a tort can be implied’ : and he illustrates his point by the well-known case of Poulton v. L. & S. W. Ry. Poulton, in terms of an arrangement which he had made with the railway company, was entitled to free carriage of a horse. At the end of the journey the local stationmaster demanded payment for the carriage of the horse; Poulton refused to pay, and the stationmaster detained him. The Court of Appeal held that the railway company was empowered to detain goods, but not persons, for non-payment of carriage; that accordingly they had no power to detain Poulton, even on the assumption that he had wrongfully taken the horse by train without paying; that there could be no authority for the arrest implied to the stationmaster; and that his employers were not liable for his tortious act.