Johnson's last proposal, though following almost naturally from what had gone before, well-nigh staggered the postmasters-general. It was that, in order to carry his plan into effect, the number of penny post letter-carriers should be more than doubled. The existing number was eighty-two, and the number which Johnson proposed was 181. This, even at the present time--large as are the numbers with which the Post Office has been accustomed to deal--would be considered a heavy, an exceptionally heavy, increase. In 1793 it was regarded as portentous, and the postmasters-general anxiously sought means to reduce it; but Johnson, besides being perfect master of his subject, possessed two faculties which by no means always go together. He possessed the faculty of devising a good scheme and the faculty of explaining it; and the lucid explanation he now gave convinced the postmasters-general that they could not do better than adopt his plan in its entirety. Contrasting the time which a letter took to pass between various parts of London with the time which it would take if his suggestions were adopted, Johnson had no difficulty in shewing that from his plan the public would derive facilities for intercourse to which they had hitherto been strangers. There were, perhaps, no two places between which the course of post was more difficult to manage than Marylebone and Limehouse. Under the existing plan a letter from one of these two places, however early it might be posted, might not reach the other on the same day, and, even if it did so, an answer could not be received before the afternoon of the following day. Under Johnson's plan a letter might be received, an answer returned, and the answer answered, all on the same day. Places less inconveniently situated in relation to each other were to receive a still larger measure of benefit. Between persons residing in Lombard Street and the Haymarket, for instance, five letters might pass to and fro between the hours of eight in the morning and seven in the evening. This was within the town limits. Within the country limits the general effect of Johnson's plan may be stated thus: that to letters from London answers might be returned sooner by two posts if the letters were for places not more than five miles distant, and, if for places distant between five and ten miles, sooner by a period ranging from one to three days. The last-mentioned places, moreover, were to have three posts a day instead of one post.