The running of these mail-coaches had a powerful influence on the whole question of road improvement, since the attainment of the best possible speed and the avoidance of delays in the arrival of the mails came to be regarded as matters of supreme importance; while more and more of the ordinary stage-coaches were put on for travellers to whom the lower fares[10] were of greater concern than high rates of speed. Mail coaches had the further good effect of stimulating great improvements in coach construction. The use of springs, in particular, allowed of a more compact vehicle, carrying luggage and outside passengers on the roof instead of relegating them to a basket "conveniency" behind. The competition, or, at least, the example of the mail-coaches had the further result of increasing the speed of the "flying" coaches, {57}which now generally aimed at doing their eight or nine miles an hour; but here, again, much depended on the state of the roads. Supplementary to the coaching there was the system of "posting," favoured by those who did not care to patronise public vehicles, and could afford the luxury of independent travel. In the earliest form of the posting system, that is, in the days when wheeled vehicles had not yet come into general use, and people did their journeys on horseback, travellers hired horses only at the recognised posting places; and Fynes Moryson, in his "Itinerary," narrating the conditions in 1617, says a "passenger" having a "commission" from the chief postmaster "shall pay 2½d. each mile for his horse and the same for his guide's horse; but one guide will serve the whole company, tho' many ride together." Travellers without a "commission" had to pay 3d. a mile. The guide, presumably, brought back the horses, and, also, really guided the traveller--a matter of no slight importance when the roads were often simply tracks over unenclosed spaces with no finger-posts to point the way. Another form of posting was the hire from place to place of horses for use in private carriages; but the more general form was the hiring of both horse and post-chaise--a four-wheeled vehicle, accommodating, generally, three persons, and having a roof on which luggage could be strapped. Posting was a costly mode of travelling, only possible for people of wealth and distinction. Harper calculates that to "post" from London to Edinburgh must have cost at least £30; but it was no unusual thing, about the middle of the eighteenth century, for the Scotch newspapers to publish advertisements by gentlemen who proposed to "post" to London, inviting others to join them with a view to sharing the expense.