1842.J 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



07 



in succession, howcil to llic Roman yoke — yet. as momimenis of tlic highest 

 degree of art an'l civilization of ihose ages, must tliey he admired by all, and 

 may be usefully studied by the ('n;;incer of the present ilay — few of whose 

 constructions, even ihe gigantic railway, will probably endure as some of the 

 Roman roads have done — such as the Appian Way, for instance — through 

 the long period of nearly 2.00O years. The number and extent of these roads, 

 made by the first conquerors of Albion, through Uiis island, have only been 

 ascertained and appreciate 1 since the publication of the magnillccnt maps of 

 the Ordnance Survey by the corps of Royal Knginecrs, by those who have 

 studied their beautiful and surprising .accuracy, and their minute topogra- 

 phical details, which enable a curious inquirer to trace, by tlieir remarkable 

 straightness of course, these ancient routes, through woods ami remote dis- 

 tricts, and over wide ranges of hills, where their origin. e\en in tradition, is 

 now forgotten, and where the long lane, grassed over and forsaken, from its 

 steepness or sec1u>ion, accurately laid down, m its true course, by Ihe science 

 of the present day. marks, at intervals, over whole counties, Ihe former line 

 of the sl.ilely march of the Roman soldier. I!ut it remains to this day an 

 unsolved problem in engineering, to discover by what uicaiis these roads were 

 laid out in such perfect truth of direction, tlirouRli the thick and trackless 

 forests which then covered the whole island. It h.as been observed, that it is 

 one of the most dilllcult points for a political economist to define, with any 

 degree of certainty, the line of demarcation between public and private enter- 

 prize, in theejiccuiiiin of works of internal improvement. In a former lecture, 

 he observed that it was undoubtedly owing to the cslablishment in Fr.-ince, 

 by Richelieu, of the Hoard of Roads and Bhilges. that that country was in 

 possession of e.\cellent roads long before the principal part of Europe ; he 

 might have added, also, canals — at least, before weliad them in Great Britain. 

 and yet have a good reas<m to believe that, at the presi-nt lime, that very 

 establishment is a serious obstacle in retarding the introduction into France 

 of tlic modern system of improvement of internal communications, by para- 

 lysing the self-dependence of the districts. In this country, the very opposite 

 system, of leaving a!most everything to private enterprise and individual 

 e.\erlion, has been mist strikingly successful, and has fostered and matured 

 the talent, the ingenuity, the skill, and the experience of the civil engineer, 

 from Ihe competition cealed by the necessity of individual exertion, which 

 it is prcsimed would not have been developed, had he been a Government 

 dependant. The origin of the system of forming and repairing roads by 

 trustees, and the collection of lolls for that purpose at turnpike g.ales, dates 

 somewhat more ihan a century lack, and the rapid improvement of our 

 internal communications, both by land and water, about that time ; and it is 

 a remarkable fact, that, when land was of comparatively small value, it was 

 more difficult to obtain ground for a new road than at present, when a square 

 yard of land sometimes costs more than would have purchasctl a rood in 

 former days ; and w hen one of the public objections seriously urge<l was, 

 that if so m.any riLids and canals were made, it would diminsb the quantity 

 of land required for agricultural purposes ! But, happily, general knowledge 

 has been dilTustd. and the former prejudices have yicliled to calculation, as 

 man has ac<)uired a knowledge of Ihe value of time, and has found that the 

 payment of turnpike tolls, for gi.otl and level roads, is cheaper than to keep 

 extra horses to drag his teams up steep hills, or through marshy ruts. The 

 Professor next staled, ihat he should not go into the dclriil, either of the lay- 

 ing out, or the construction of roads, but be must add a few observations, as 

 connected with the duties nf an engineer, in regard lo some of ihe general 

 principles. He should accommodate a new line of road lo local circum- 

 stances, so far as could be without superseding public advantages. It would 

 be ridiculous to follow the old Roman fashion, on the mathematical axiom, 

 that a straight line is the shortest that can be drawn between two points. 

 This would not make Ihe most commodious road— hills must be avoided, 

 towns must lie resorted to, and the sudden bends of rivers must be shunned. 

 It is not .suggested that roads should be made serpentine, merely for Ihe sake 

 of the picturesque; but the skill of the engineer is to be exerted in avoiding 

 irregularities of ground and irregularity of inclinations, and he will generally 

 find, that a strict adherence lo a slraight line is of much less consequence 

 than IS usually supposed, even in actual dist.anceover long lengths. It was 

 well known that a blind man was, some years ago, ailvantagei usly employed 

 through Yorkshire and Derbyshire, in laying out ro,ids through tho.se hilly 

 counties. He followed the streams which made their way amongst Ihe hills, 

 and, by finding out the chonls of such arcs, or bends of Ihe river, as passed 

 on practicable ground, he succeeded in his attempts. It is obvious that, when 

 the arc described by a road going ever a bill is greater than that described 

 by going round it, the circuit is preferable ; but it is m.t known lo the ordi- 

 dinary ro.ad surveyor, though it ought to be ingrafled in Ihe mind of the 

 engineering student, that, within certain limits, it would Ix' less laborious lo 

 go round the hill, ihougli the circuit be much greater than lhat which w ould 

 be m.adc in crossing it. Thus, when a bill has an ascent i.f no more than unc 

 loit :n Ihirty, the thirlicth part of the whole weight of the carriage of Ihc 

 load, and of the horses, must be lifted up, whilst they ailvaiice thirty feet. 

 In doing this, one thirli«th part of the w bole load continually resists the horses' 



draught : and thus, in drawing a waggon of six Ions weight, a power to 

 overcome resistance equal to the force of two additional horses must be 

 e.verlwl. But what is here said of level roads must not be str-oined into an 

 assertion that a perfectly level road is always the best for every description 

 of draught or load. Allernations of rising and level, or of falling ground , 

 are serviceable to horses moving very swiftly ; the horse has time to rest his 

 lungs .and ditferent muse es, and of ihis the experienced driver knows how to 

 take advantage : but while this qualification is made, care must Ije taken not 

 to strain it too much, as did one provincial road maker, who very ingeniously 

 carved a naturally quite level road into a series of short billowy undulalioiis, 

 which his successor h.ad lo level again. Without tr.-ivelling through the 

 whole history of road improvements, he mi^-ht state that Telford in England 

 and Scotland, and in Ireland. Nimiiiu, GrilTiths, and tilgeworlh, brought the 

 laying out and eonslruclion of roads lo the present perfection ; and of the 

 writings of Ihe latter he had availed himself in many of Ihe prece<ling oljser- 

 v.ations. The many roails of Great Britain were just arrived at almost the 

 highest degree of perfection, when again the increased .ippreciation of the 

 value of time led speculators to conceive, and our engineers to realize, the 

 idea of the employment of iron surfaces for roads. Before, however, follow- 

 ing the gradual transit of roails into railways, he would make a few oljser- 

 vations on the other branch of international communication— the navigable 

 river and the canal. 



Tlie tiistes and speculations of the last fifteen years have l)een so exclu- 

 sively ilevoled to railvv.iys as Ihe fashionable mode of internal communication, 

 that canals have almost l>een lost sight of, and it is now nearly forgotten by 

 the modern speculator, though it may be interesting to the young engineer 

 to be informed, that fifty years ago the mania for constructing canals and 

 improving river navigation was as great, even if not greater, lhan the enthu- 

 siasm displayed very recently about railways. Parliament was then deluged 

 with applications to grant Acts of Incorporation for canal companies; the 

 press teemed with canal publications, the shop windows were filled with canal 

 maps and sections, and the papers and periodicals with adverlisements and 

 paragraphs on canalization. Canals appear to have been duly appreciated in 

 ancient times, and used for the purpose of drainage, irrigation, supply of 

 water, .and navigation, (ii bis former introductory lecture he alluded to the 

 canal of Xer.\es, at the foot of Sloiuit Athos— an attempt wh eh is stated lo 

 have been renewed by the Roman emperors in later ages. A canal navigable 

 for large boats was constructed by the Ptolemies between the Nile and the 

 Red Sea, though it is doubtful whether ihe state of engineering skill in those 

 days perm tied an .actual junction to be made: this grand navigation was 

 re-opened by the caliphs in (he seventh century. Traces of it arc slill exist- 

 ing, .and lis termination in the most easterly branch of the Nile was 

 discovered by M. Bouiier, in 1707. and is still open. Under the enterprise 

 of the present ruler of ICgypt it may yet fall to the lot of an Knglish engi- 

 neer lo re-open this magnificent canal. Herodotus .assures us that the Nile 

 was in itself, or by lateral canals, navigable by the ancient Kgyptiaus for 500 

 miles above Alexandria, and the Delta of ilie Nile was formerly like modem 

 HolLind. filled with canals. The Romans m.ade more than one canal in 

 Kngland ; Ihe most remarkable was that called the Caerdykc. which united 

 the river Nene, a little below Peterborough, with Ihe river William, three 

 miles below Tiverton ; it was forty miles long, and fifty years since appeared 

 distinct enough, and must have been originally very deep; and what led to 

 the impression that this can.al was used for the purpose of internal communi- 

 cation, was lhat there was a continuation of this canal from Lincoln to the 

 Trent above Gainsborough by the Koss Dyke, which is .at Ihe present lime .i 

 fine navigable canal, Ihougli, in former times, it had been repeatedlv fdled up 

 and gone into disuse. It is believed, on good authority, thai by these two 

 canals the favourite colony of the Romans at York received their chief supplies 

 of grain. The canals of China have always excited great interest since the 

 description given of them by ilie Jesuit missionaries ; their accounts, as far 

 as regards the Great Canal running from north to south (connecting, except 

 at one short portage, C'anlon and I'ckin), have lieen completely confirmed by 

 modem travellers, particularly by Barrow, who travelled Ihe whole length. 

 Should the existence of ihe numerous lateral and other canals over the rest 

 of the country be confirmed, of w liich there is little reason to doubt, it will 

 sufficiently explain the non-existence of anything like good roails. .and the 

 almost tolal absence of wheeled carriages for goods, to which ihe iliminulive 

 and b.id breed of horses in C hina. no doubt, conlribules. There is, however, 

 a wide field opening in lhat country for the exercise of ihe skill of an enter- 

 (irising engineer, since that ingenious iwnple are as yet ignorant of the 

 niiidern lock for their canals, and when two canals meet, the diU'erenee of 

 the level is sometimes from fifteen to twenty feel, and the boats are holsteil 

 from the lower canal up .an inclined plane of smooth miaonry by capstans, 

 and slide down another into Ihe upi>or canal. The profeuor 9l.il(.<l it would 

 le.id him too far lo go much into the hisiory nf eanaU, l/iit he must allude 

 to Ihe great canals anil inland water eommunir.ition nf the Mogul country, 

 in the Ivist Imlies, made by ihe l-Jn|>eror9 .100 or 600 years since, for which 

 Ihe natural features and vast rivers ot Hindoslen alTorded great facihiics, and 



