Note 37 — I THE RATE FOR LETTERS
Reading edition
"Cross posts did not exist. Between two towns not being on the same post road, however near the towns might be, letters could circulate only through London; and the moment London was reached an additional rate was imposed. Hence the apparent charges, the charges as deduced from the table of rates, might be very different from the actual charges. Bristol and Exeter, for instance, are less than 80 miles apart; but in 1660, and for nearly forty years afterwards, letters from one to the other passed through London, and would be charged, if single, not 2d. but 6d., and if double, not 4d. but 1s. That is to say, the postage or portage, as it was then called, would consist of two rates, and each of these rates would be for a distance in excess of 80 miles."—H. Joyce, History of the Post Office, p. 29. Cf. infra, Appendix B, pp. 390-1.
This practice of charging according to the route traversed and not according to direct distance was also followed in other countries. It is perhaps comparable to the practice of computing railway charges on the basis of the distance by railway, and not as the crow flies.