It was when the Post Office required something to be done which involved transmission from place to place otherwise than on horseback that its troubles began. Such an event occurred in 1696. Sir Isaac Newton was then busy at the mint, devoting to the coinage those powers of intellect which were soon to astonish the world. The clipping of the coin had gone to such lengths that within the space of one year no less than four Acts of Parliament were passed with a view to abate the evil. Milled money was to take the place of hammered money. The clipped pieces had already been withdrawn from circulation, and now a date was fixed after which no broad pieces were to be received in payment of taxes except by weight. This date was the 18th of November, and collectors of the public revenue were allowed until the 18th of the following month to pay them over to the Exchequer. If not paid over by the 18th of December they were to be taken by weight and not by tale, and the collectors were to lose the difference. Here was a clear month's grace, and the postmasters were under a strong inducement to see that the period was not exceeded. From Oxford the hammered money was sent by barge. No sooner had it started than a severe frost set in, and lasted for six weeks, the consequence being to delay the arrival in London until the 7th of January. To take the money by weight and not by tale would have been equivalent to a fine of about £23. From this, however, the postmaster was excused on the ground that the barge was the safest means of conveyance he could have employed. As a "flying coach"--a coach which travelled at the speed of about four miles an hour--had for many years been running between Oxford and London, it must be assumed either that it had stopped for the winter or else that for some cause or other, possibly on account of highwaymen, it was not considered safe. From Sandwich, in Kent, the hammered money was sent by hoy, which did not reach the Thames until the 20th of January. Again the postmasters-general urged that the delay might be overlooked on the ground that no earlier means of conveyance would have been safe. Altogether, when the 18th of December arrived, more than £1000 of hammered money was still outstanding in the postmasters' hands; and in every case the want of conveyance or the badness of the roads was assigned as the cause.