The fossway is supposed to have led from Bath and the western regions north-east, till it joined the Ermine street. The last celebrated road was lkeneld or lkneld, supposed to have extended from near Norwich southward into Dorsetshire.
If we carefully trace the distance from the wall of .A.ntoni 'tuts in (Britain) to Rome, and from thence to Jerusalem, it will be found that the great chain of communication from the north-west to the south-east part of the empire, was drawn out to a length of 4,030 1:oman miles, or 3,740 English miles ; the public roads were accurately divided by milestones and ran in a direct line from one city to another, with very little respect for the obstacles either of nature or private property ; mountains were passed, and bold arches thrown over the broadest and most rapid streams. The middle part of the road was raised into a terrace, which commanded the adjacent country, and consisted of several strata of sand, gravel, and eemeiat. and was paved with large stones, which in some places near the capital were of granite. It is esti mated that the Romans constructed, in all, not less than 14,000 miles of paved roadway.
Since the Romans, no country seems to have surpassed or even equalled them in the hardness and durability of their roads ; in England we may presume that this branch of engineering has been carried on with greater succes of late years than in any other country of modern times ; we say of late years, for it was not until the latter half of the eighteenth century, that any cousideraDle improvement was effected ; the roads previous to that period having been of a most rude and unsatisfitetory description. The greatest share of praise for improvement in the construction of roads, is due to Mr. Telford, the eminent engineer, who reduced the practice into a system conlbrinable to the laws and requirements of science.
Practice of road-making.—The first object to be attended to in the formation of a road, is the preparing of a good solid foundation ; for on this, more than on anything else, depends the durability and convenience of the road. This premiss has been denied by some persons, and the contrary assertion put forward by Mm-. McAdam, a name which has become intimately associated with road-making, from the eircum- • stance of that gentleman having introduced into England that system which has been named after him, and is known under the title, "Macadamized." This gentleman we believe was the first publicly to maintain the opinion, that an elastic road was equally good as one with a firm unyielding surface, and not only so, but even preferable. In a publication on this subject, he says " That a foundation or bottoming of large stones is unne cessary and injurious on any kind of subsoil.
"That the maximum strength, or depth or metal, requisite for any road, is only ten inches.
"That the duration only, and not the condition of a road, depends upon the quality and nature of the material used.
" That freestone will make as good a road as any other kind of stone.
"That it is no matter whether the substratum be soft or hard." In contradiction to such aiisertions as these, we have the universal experience of practical men, and the testimony of both practical and scientific men, such as Telford and La rd n er.
To comprehend thoroughly the great importance of making a regular and strong foundation, it should he home in mind that roads are structures that have to sustain great weights, and violent percussion; the same rules, therefore, ought to be followed with them as are followed with regard to other structures. A road will never be of long duration, nor at any time in a satisfactory condition, which has not a firm and substantial foundation. But tint is its durability atlimed under such circumstances, it has disadvantages in other points equally important and essential to a good road way. Besides the durability of a structure, we have to con sider its economy, and its adaptation to the special purpose for which it is intended. Now, the object to be attained by a good road is the conveyance or transport of goods in the readiest and most economical matinee, so that the constantly occurring expense of transit ought to be taken into even more careful consideration than the original outlay upon the road itself; we want goods to be conveyed at as small an expense as possible. Now, the largest item in the expendi ture for the conveyance of goods consists in the expense of the power employed ; and as much as we can reduce the amount of this power, by so much du we reduce the expense likewise. According to all experience, as well as science, the power required to draw a carriage, or any body, over a yielding or elastic surface, is much greater than that required to draw the same over a hard unyielding surface ; and the reason is plain—there is not so much friction in the latter case as in the former, and the surface in contact with the wheels of the conveyance is not so great as on a yielding roadway. "The resistance," says Professor Leslie, which friction occasions, partakes of the nature of the resistance of it consists of the consumption of the moving-force, or of the horse's labour, occasioned by the soft surface of the road, and the continually depressing of the spongy and elastic substrata of the road. In fact, on a yielding roadway, the carriage or waggon has to be drawn over a series of hillocks, for, as the load passes over it depresses that portion of the road immediately beneath it, and has before it, to be passed over in its turn, a portion which has not yet undergone this process: the comparison between the tractive power employed on roads of different elasticities, has been well thus:—Au ivory ball set in motion with a certain velocity uremia turkey carpet, will sutliNr a visible relaxation of its course ; but with the same impelling force it will advance farther, if rolled over a superfine cloth; still farther over smooth oaken planks; and it will scarcely seem to abate its velocity over a sheet of tine ice." The Ilia of greater tractive power being required in elastic titan in hard roads has been proved beyond a doubt, by the experiments made by Sir John Macneil, by his machine invented for this purpose.