It was an essential part of Witherings's plan that the posts should be not only regular and certain but also self-supporting. During the earlier part of the century they had been maintained at a cost to the Crown of £3400 a year, and this was a burden which the Crown was no longer in a position to bear. That they should be made to pay their own way was, therefore, an indispensable condition. But how was this to be accomplished? Witherings's sagacity left him at no loss for a reply. He discerned that to carry a letter is to perform a service for which a payment may fairly be demanded in return; and that the demand would meet with a ready response must have been plain to him from what he saw going on in the west of England. In 1633, or two years before he produced his plan, the Mayor and Aldermen of Barnstaple had set up a post between their town and Exeter. This post was to leave Barnstaple every Tuesday at 7 o'clock in the morning, and to be in Exeter early on the following day, in time to catch the King's post on its way from Plymouth to London. The King's post was maintained at the expense of the King; but for the local service, as a means of defraying the cost, the Corporation imposed a small charge, a charge of 6d. for a single letter and of 8d. for a double one. Other towns in Devonshire had adopted a similar course. That Witherings was aware of the existence of these posts is evident from the special allusion that is made to them in the Proclamation which he prevailed upon the King to issue;[5] and it was their success, probably, which suggested his own undertaking. Concluding that what private enterprise was effecting on a small scale the State would be able to effect on a large one, he proposed--and the proposal received the royal sanction--that for every letter sent by post a "port" or charge for carriage should be levied after the following rates:-- +-------------------------------------------------------------------------+ | |Single Letter.|Double letter.|"If bigger."| +------------------------------+--------------+--------------+------------+ |Under 80 miles | 2d. | 4d. | 6d. an oz. | |80 miles and not exceeding 140| 4d. | 8d. | 9d. " | |Above 140 miles | 6d. | 12d. | 12d. " | |To or from Scotland | 8d. | ? | ? | |To or from Ireland | 9d. | After two ounces, 6d. the | | | | ounce. | +-------------------------------------------------------------------------+ [5] The Proclamation enjoined that on letters "to Plymouth, Exeter, and with the two other places in that road," Witherings should "take the like port that now is paid, as near as possibly he can."