When the road was carried over marshy ground, a framework of carpentry was provided, called 'contignata pavimenta,' and the frame itself contignationes. The joists or sleepers were termed coaxationes or cassationes, and were made of an oak called esculus, because it was not liable to warp or shrink. To protect the timber from the effect of the lime mixed with the other materials, it was covered with a bed of rushes or reeds, and sometimes straw. On this stratum of reeds or straw was laid the statumen or foundation. The second bed was made of broken stones mixed with lime, which Isidore calls rudus. When this material was composed of stones freshly broken, it was called rudus novum, and quicklime was added in the proportion of one of lime to three of stone. But when the material came from old buildings, it was called rudus redivivum, and then an additional portion of lime was used, two parts to five, and the work termed ruderationem; the rammer or beater was employed to strengthen, equalize, and smooth it. This composition, whether formed of gravel or débris, was 9 inches in thickness. after it had been thoroughly rammed. 7.9 15.6 -36 Roman-feet-. FIG. 1.-Cross-section of Roman road ('Appian Way'). Over this tarras or ruderation, a cement was laid for the third bed, which was composed of bricks, potsherds, or broken tiles mixed with lime, in the proportion of one of lime to three of brick. This was spread over the ruderation in a thin layer to receive the fourth bed or paving, consisting of polygonal blocks jointed with the greatest nicety, serving as a covering to the entire work, and was called in consequence summam crustam. The third bed, or nucleus, was the softest layer of the whole, and was interposed between the harder layers. The stones and cement which formed the road were not less than 6 inches in thickness, and the entire mass laid upon the framework of carpentry was 15 inches. Fig. 1 shows a cross-section of the Appian Way,' and typifies many of the other great military roads in the neighbourhood of Rome. The paved portion was 16 feet wide, with margins on either side, separated by a curb 2 feet wide and 18 inches high, which served as seats for travellers. The margins were not paved with blocks, the finished surface being the gravel concrete; they were consequently at a lower level than and were only half the width of the centre portion. The entire width of these military roads was from 36 to 40 Roman feet, the middle portion being for the infantry, while the margins were made use of by horses and carriages. Of the other great military roads some were named after the Consuls and Emperors who had constructed them, such as the Flaminian and Domitian, while others were designated by the name of the province through which they passed, such as the Latian, Tiburtine, Campanian, and Praenestine ways. Other roads constructed solely for civil purposes were connected with the great military ways and distinguished by the following names, Via, Actus, Iter, Semita, Trames, Diverticulum, Divertium, Callais, etc.* Via answers to our common road; its breadth was 8 Roman feet, so that carriages could pass without collision. Actus was a road for the passage of a single carriage; it derived its name from a measure used in surveying land, of which the breadth was 4 feet and the length 120 feet. Iter was a road for pedestrians and horsemen, the breadth of which was 3 feet. Semita was only half the breadth of the Iter, and when it crossed fields it was called Trames, Diverticulum, and Divertium. Callais was a road through mountainous districts, for the purpose of attending the flocks. "The unpaved roads of the Romans were called by Ulpian vias terrenas, to distinguish them from those dressed with stone or gravel, and they were regulated by similar laws and ordinances to the others. The road from Spain into Italy, through Nismes, was of this kind, and only passable during the summer months. "In the winter and spring it was in a soft state, from the water which came down from the neighbouring mountains, though Strabo mentions. several wooden and stone bridges and ferries. These roads, so liable to be broken up by the torrents, were exposed to the action of the sun and wind, all shade being removed, that they might speedily dry. "The whole Roman Empire comprised eleven regions, viz., Italy, Spain, Gaul, British Isles, Illyria, Thrace, Asia Minor, Pontus, the East, Egypt, and Africa, and these were divided into 113 provinces, traversed by 372 great roads, which, according to the Itinerary of Antoninus, were together in length 52,964 Roman miles." † In Peru the Incas appear to have built great roads. That from Quito to Cuzco was between 1500 and 2000 miles in length and 20 feet wide; it was situated at an elevation of over 12,000 feet above the sea level. This road was characterized by having a running stream and a row of trees on either side, while the road itself was paved with stones 10 feet square, and in some instances with stone covered with bitumen. * Cresy's Encyclopædia of Civil Engineering, 1847. + Ibid. Humboldt, in his Aspects of Nature, speaks of this mountain road as "a marvellous work, not inferior to the most imposing Roman roadways"; while Prescott, in his History of Peru, says of this road that "it was conducted over sierras covered with snow; galleries were cut through the living rock; rivers were crossed by means of bridges swung suspended in the air; precipices were scaled by stairways hewn out of the native bed, and ravines of hideous depth were filled up with solid masonry." Among the many magnificent engineering works carried out by the Romans, the public roads ranked pre-eminently high, and great labour and expense were incurred in their construction. It is not to be wondered at, therefore, considering the importance of these works, that only those of the highest attainments were considered as having the necessary qualifications to supervise these great works of prominent utility. Early French Roads.-As the Romans conquered states, roads were introduced for the benefit of commerce and society, and the art of constructing them on the Roman method was practised in France till about the beginning of the eighteenth century. A cross-section of these roads is shown in fig. 2. The material forming the road was composed of flat stones laid by hand Broken stones Stones laid flat by hand FIG. 2.-Cross-section of French road (Roman method) previous to 1775. in two or more layers for a width of 18 feet on the bottom of the excavation; on this foundation a layer of small stones was spread and beaten down, and the surface finished with a layer of stones broken smaller than the underlying material. The usual thickness of the body of the road was 18 inches in the centre and 12 inches at the sides. The roads in France down to the year 1764 were maintained by statute labour (la corvée) which was only effected twice annually, in the spring and autumn of each year, necessitating the application of large quantities of stones to carry the traffic during the intervals between repairs. After the suppression of statute labour (1764) the mode of constructing new roads was considerably modified, and in the year 1775 M. Trésaquet adopted the method shown in section at fig. 3. The excavated portion was made parallel to the finished surface of the road and 10 inches below it. The bed of stones was laid edgewise and beaten to an even surface, over which a second bed of smaller stones was laid by hand, the finishing layer being of broken stones the size of walnuts, and spread with a shovel. The rise of the road was 6 inches in the centre, the material for finishing the road or upper surface being selected from the hardest quality of stone. FIG. 3.-Cross-section of French road, as constructed by M. Trèsaquet in 1775. Later French Roads.-This mode of constructing roads in France was practised till about the year 1820, when the system of Macadam attracted attention; the peculiar virtue of angular broken stones in consolidating and forming a hard surface was recognized, and the system was officially adopted in 1830 for constructing roads in that country. M. Dumas, engineer-in-chief of the Ponts et Chaussées, writing in 1843,* stated that the system of Macadam was generally adopted in France, and that the roads were maintained in good condition by continuous and watchful attention in cleansing and repairing them, and realizing his motto, "The maximum of beauty." Early British Roads. The great Roman General Julius Cæsar carried out many paved roads in Italy, and, recognizing the vital importance of such lines of communication, extended them into the provinces; while subsequent to the year A.D. 43, main and branch roads were constructed in Britain by the Romans in almost every direction, from their military stations and camps to the coast. "The Romans seem to have paid particular attention to the construction of roads in the distant provinces; and those of Britain, which may still be traced in various ramifications, present a lasting monument of the justice of their conception, the extent of their views, and the utility of their power. A grand trunk, as it may be called, passed from the south to the north, and another to the west, with branches in almost every direction that general convenience and expedition could require. What is called Watling Street led from Richborough, in Kent, the ancient Rutupiæ, north-east, through London to Chester. The Ermine Street passed from London to Lincoln, thence to Carlisle, and into Scotland. The Foss Way is supposed to have led from Bath and the western regions, north-east, till it joined the Ermine Street. The last celebrated road was 'Ikeneld' or 'Ikneld,' supposed to have extended from near Norwich, southward into Dorset. shire." † Although there is no trace of Roman influence in the construction of later roads in Britain, still in many cases those made by them form the *Annales des Ponts et Chaussées, 1843. + Pinkerton's Geography, vol. i. p. 20. foundations of existing roads in different parts of the country. Many traces of the remains of Roman Roads, often situated at a considerable depth below the surrounding ground of the present day, have been discovered from time to time. One of the latest discoveries was disclosed when carrying out storm-water drainage works at Rochester in 1897, the details of which may be given. "When the Romans made the great way from the Kentish coast to the north of England, a wooden bridge, built upon piles, was thrown across the Medway. On reaching the Strood side of the river the engineers were confronted with a marsh of about 355 yards in width. This difficulty they boldly overcame by constructing upon the alluvial deposit a magnificent causeway. "A section of the buried work showed the following:-(1) Layers of post-Roman roads for a depth of 2 feet 8 inches; (2) paved surface of causeway, 6 inches to 8 inches; (3) small pebble gravel, mixed with black earth, rammed, 9 inches; (4) flints, broken fine, 7 inches; (5) rammed chalk, 5 inches; (6) flints (white, and rather large), rough pieces of Kentish rag, fragments of Roman tile, 3 feet 6 inches; (7) marsh mud, containing numerous oak piles about 4 feet in length, with pieces of wood laid at intervals across them, or perhaps they were originally made fast by nails. The width of the causeway was about 14 feet, while the distance apart of the wheels of the waggons has been estimated, from the grooved wheel-track, at 4 feet."* The construction of this part of the road passing through Rochester corresponds very nearly with that described at page 3, and designated contignata pavimenta, being the method adopted by the Romans when forming roads across marshes in Italy. The depth of the material forming the roadway, above the timber foundation, amounting to 5 feet 10 inches, appears to be considerable greater than that usually adopted by the Romans in similar circum stances. For a considerable period after the occupation of Britain by the Romans the roads made by them were the only means of internal communication, but during the Dark Ages they were allowed to fall out of repair and finally into ruin, and were in many instances overrun with forest and waste until they assumed a condition probably the worst in Europe. At this period communication between towns was both difficult and dangerous; the roads which formerly had such a beneficial effect on the country were regarded with terror as aids to plunder, and in the year 1285 owners of land were enjoined to widen the roads, by cutting down trees on each side to a certain width, the inland commerce, such as it was, * The foregoing description is abstracted from a pamphlet on "Roman Discoveries," by G. Payne, F. L.S., F.S. A., reprinted from Archæologia Cantiana, 1898. |