The King's messengers fought hardest against the innovation, but without success. Finding the expense of their journeys to Berwick and Holyhead appreciably increased, they appealed to the Treasury for redress, and the Treasury invited the postmasters-general to explain under what authority they had raised their charges. The postmasters-general replied, as they had replied scores of times before on occasions of complaint from the public, that they had really nothing to do with the matter; that it was the postmasters who made the charges; and that in the opinion of the Attorney-General these officers were clearly entitled to be paid according to the new measurements. It had been expressly provided by Act of Parliament that all persons riding post should pay after the rate of 3d. for every British mile, and the British mile was a known statute measure common to all His Majesty's dominions. The Treasury were not satisfied, and insisted that the King's messengers should be charged according to the old scale. But this, as the postmasters-general pointed out, was not feasible, the Act of Parliament by which they were governed making no exception in favour of particular persons, but on the contrary enacting that all persons without distinction should pay at the rate of 3d. a mile. At the headquarters in Lombard Street it was long feared that, on finding that the reputed mile exceeded the statute mile, those postmasters whose remuneration had been fixed according to the distance over which they carried the mails would claim an increased mileage allowance; but this, to their credit be it said, they never did. Such forbearance, however, had one ill effect. It tended to perpetuate error. For many years afterwards two sets of distances remained in vogue, the one right and the other wrong; the new set applicable to travellers, and the old set to mails and to expresses sent on the service of the State.[49] [49] This explains why in the Road Books of the time the distance between two places is stated differently in two parallel columns under the initials C and M, the one being the computed and the other the measured distance.