ROAD. Under this head it is proposed to embrace road-making, with a brief sketch of the history of roads, referring for more detailed statistical information to the GEOORAPMCAL DrvIsroN of this work, and to WAY and Tunfirmo TRUSTS for an explanation of the laws respecting the formation and maintenance of the highways in this country.
The importance attached to roads by the great nations of antiquity is abundantly testified by historians, though, except in the case of the Roman roads, there are few remains existing. The Carthaginians are said to have been the inventors of paved roads, which were much used by the Romans, who were distinguished by the vast extent and solid construction of their highways, of which several thousand miles were made in Italy alone, while every country which was brought under their sway was more or less intersected by these channels of com munication. Though formed mainly to facilitate military movements, the Roman roads were productive of the greatest civil benefits. Being made by a power whose resources were almost unlimited, these military roads were usually laid out in straight lines from one station to another, with little regard to natural obstacles, which were frequently passed by means of very extensive works, as excavations, bridges, and in some instances, tunnels of considerable length. The solidity of their construction was fully equal to the boldness of their design ; fact proved by the existence of many that have borne the traffic of near two thousand years without material injury. The Roman engineers were very particular in securing a firm bottom, which was done when necessary by ramming the ground with small stones, fragments of brick, &c. On this carefully prepared foundation a pavement of large stones was firmly set in cement, the stones being occasionally squared, but more commonly of irregular shapes, though always accurately fitted to each other. For this purpose many varieties of stone were used, but the preference seems to have been given to basalt, where it could be had, it being used in many situa tions in which other suitable materials might have been procured with less labour and expense. Where large blocks could not be con veniently obtained, small stones of hard quality were sometimes cemented together with limo, forming a kind of concrete, of which masses extending to a depth of 'several feet are still in existence. The
Roman roads were generally raised above the ordinary surface of the ground, and frequently had two carriage tracks separated by a raised footpath in the centre.
In some parts of the continent of Europe, especially iu Italy, the Roman system of road-making has been imitated, particularly in city pavements ; but in Britain the attempts to follow the Roman model appear to have been very limited, and road-making has been very imper fectly practised till within the last half century. Many of the existing highways were originally mere paths or tracks from place to place, their course) having been determined more by accidental circumstances than by a due attention to the properties of a good road. Thus deviations were made from the direct course in order to cross rivers at fordable points, and the road was conducted over a hill in preference to a more level course round its base, to take advantage of natural drainage. As found anywhere ; but if such a road could be found, and if it were curved, so as to prevent the eye from seeing farther than a quarter of a mile of it, in any one place, the whole road would not be lengthened more than one hundred and fifty yards." The principle explained in the article RAILWAY, of so arranging the inclinations on each side of the summit, or highest point unavoidably passed over, that there may be no unnecessary rise and fall, is equally deserving of attention in the design of a common road, although it has been much neglected. The following statement respecting an old road in the Isle of Anglesey, which was altered by Telford, shows how very much a road may be improved by judicious alterations ; not only by shortening the line and lowering the summits, but also by diminishing the minor undulations improvements have been introduced in the systems of construction repair, the direction and levels have been frequently left unaltered, to avoid the temporary inconvenience and expense attending a devia tion from the established course. The scanty information we possess as to the state of the roads in early times indicates that it was very bad ; and after the introduction of turnpikes, and even down to the oanniencentent of the present century, the greater part of the roads were, owing to injudicious modes of construction and repair, in a state very unfit for traffic.