ROADS. 



3.07 



Principal 

 cauiewajf 



Roadi and angular pieces of a variety of forms, which more easily 

 Hlghwnyt. give place to the pressure of a carriage- wheel than the 

 V*y^ boulder or rouiulcil stones, of which the Romans made 

 general ue, and which are still applied to streets both 

 in I. upland and Ireland. These stones, having a 

 broad seat or bed, are not easily misplaced, though 

 they make a very rough, noisy, and unpleasant 

 path. 



Perhaps the finest specimens of the aisler causeway 

 to be met with in the united kingdom, nre those of the 

 Commercial Hoad of London ; (m-at Sackville Street, 

 in Dublin, and Leith Walk of Edinburgh. The traffic 

 upon the whole of these streets is great. The latter forms 

 almost the only thoroughfare to the port of Edinburgh. 

 It is regulated by a special Trust, and its toll is ge- 

 nerally rented at about L.5000, per annum. The 

 causeway of Leith Ua'k is nearly two miles in length, 

 its breadth between the kirb-stones, which line off a 

 spacious foot-path on each side, may be taken at the 

 average breadth of fifty-seven feet. The stones of which 

 it is paved are of a cubical form, of the largest dimen- 

 sions of aisler causeway, laid upon a bed of sharp sea- 

 sand, free of earthy particles, measuring twelve inches 

 in depth. It is now fourteen or fifteen years since 

 Leith Walk was converted, from a very bad common 

 road, into a spacious causeway, and although its sur- 

 face now exhibits many inequalities, yet it has con- 

 tinued during that comparatively long period, and may 

 continue as long, without requiring any considera- 

 ble repair. Now, if we compare this with the conti- 

 nual repair to which all metal roads, with a traffic simi- 

 lar to that of Leith Walk are incident, we presume 

 that the metal would require to be renewed at least 

 every third year. It must, therefore, have cost, upon 

 the whole, a much greater expence than causeway, in- 

 dependently of the inconvenience which attends fre- 

 quent operations of this kind upon such a thorough- 

 fare ; and its annoyance from dust, &c. 



If, therefore, we can suggest a system of road mak- 

 ing which shall secure to us all the advantages of a 

 smooth and uniform railway, with the ultimate econo- 

 my of the aisler causeway, we conceive that much 

 shall have been gained, towards the facility of car- 

 riage, and the comfort of travelling. This we propose 

 to effect by laying stone tracks, if not throughout 

 the whole extent of certain principal roads, at least 

 upon all their acclivities. These undulations oblige 

 the carrier to modify his load, perhaps to one- half of 

 what he could take upon a level road. If, in the same 

 manner, the streets of towns and villages situate on the 

 highway were laid in this manner, the traveller would 

 pass smoothly along at his case, instead of the thunder- 

 ing noise and jolting motion so irksome to himself, and 

 dangerous and annoying to the respective inhabitants. 

 Nothing is more common than the expression, " Now 

 we have got off the stones we shall be safe and com- 

 fortable." The writer of this article remarks, in proof 

 of this, that, in the course of his numerous journeys, he 

 has been thrice in a carriage broke down, and upon 

 two of these occasions he was passing along a city 

 road. 



We have already remarked that some of the Ro- 

 large stones man highways were formed with squared materials 

 inconeni. o f J ar g e dimensions, as is still the case in Milan, 

 and other cities of Italy. Several tracks of stone- 

 rails of limited extent are to be met with in various 

 parts of Britain ; the stones of which these railways 

 are composed, generally measure from three to four 



Wheel- 

 tracks of 

 tone. 



Use of 



ent. 



feet in length, from ten to twelve inches in breadth, 

 and from eight to ten inches in depth. In the neigh- 

 bourhood of Aberdeen there is a granite railway : 

 description, which runs several miles along, or in con. 

 junction with, a common metalled road. But we ob- 

 serve that, unless stones of such lengths as three or four 

 feet be deeply seated in the ground, and altogether 

 contain as large a mass of rock as those of Italy, in 

 proportion to the greater weight of English carriages, 

 they will be too weak for their length, and it wilt 

 hardly be possible to keep such rails firmly in their 

 places, and in this way the chief benefit of a con- 

 nected railway will be lost. Besides, large stones are al- 

 ways more difficult to be procured, transported, and 

 laid in their places, than stones of smaller dimensions. 

 An objection of no small importance also occurs in the 

 use of these large materials, from the danger there is 

 of horses slipping their feet and coming down upon the 

 road. To avoid this, the practice in Italy is to keep 

 the stones in a rough state, by occasionally cutting 

 grooves upon the upper surface with a pick-axe, when 

 they get into a smooth state with the carriage- wheels. 

 This mode of paving with large blocks has in some 

 instances been practised on a small scale in London, 

 with granite ; but in order to give stones of this kind 

 he necessary stability, the blocks would require to be 

 cubes, or to have their dimensions equally large on all 

 their sides, which, upon the whole, would be attended 

 with a great expence. 



It appears from the reports of the committee of the 

 House of Commons, on the improvement of roads and 

 highways, that Mr. Henry Matthews, of Walworth 

 Common, proposed a plan for stone-railways upon an 

 extensive scale, for the principal highways of the king* 

 dom. The stones which he was to employ, were to 

 measure about four feet in length, ten inches in depth, 

 eleven inches in breadth at the top, and fourteen inches 

 at the base. At the points of contact the stones of 

 some of these tracts were to be connected with a smal- 

 ler block, by a kind of mortice-formed joint, similar 

 to those represented in Figs. 5, 6, and 7, Plate 

 CCCCLXXX. and described at the end of this article. 

 The expence of Mr. Matthews' plan was probably one 

 of its chief objections, having been estimated at L.I, 5s. 

 per lineal yard for each set of tracks. It would pro- 

 bably also have been found in practice, that unless the 

 cubic contents of these blocks had borne a greater pro- 

 portion to their length, they would not have withstood 

 the necessary pressure of carriages. 



In the several examples of this description of rail- 

 way which we have met with, the stones have always 

 been of considerable lengths. Now, it appears to us 

 that, by introducing numerous joints, we shall not 

 only secure the safety of the horses, and prevent the 

 risk of their falling, without the trouble of cutting 

 grooves in the stone, but that by keeping them of a 

 length not exceeding that of the best aisler causeway, 

 we shall, at a moderate expence, be able to procure ma- 

 terials proportionable in all their dimensions, and which 

 can be easily kept in their places. This will be more 

 readily understood when it is considered that a car- 

 riage-wheel impinges or rests only upon about an inch 

 of its track at a time in the course of its revolution. 

 There is, so to speak, a kind of compensating effect, 

 connected with the use of small stonee, which prevents 

 the tremour from being communicated beyond the 

 limited sphere of a few inches, instead of several feet. 



In the Transactions of the Highland Society of 



Plan by Mr. 

 Matthews. 



PLATE 



CCCCLXTX. 

 Figs. 5, 6, 7. 



Plan by Mr. 

 Slercnsco. 



