354 



ROADS. 



Roads and bringing the various objects of an interesting nature into 

 Highway*. v j ew> j n public roads however, this should very 

 <_. *""'. rare jy enter into the design of the engineer, though 

 other considerations, such as a more easy line of draught, 

 a more suitable tract of ground, or the vicinity of good 

 materials, will sometimes properly induce the adoption 

 of a less direct course. The Roman roads were chiefly 

 laid out in long straight lines, and the engineers of 

 France, and other continental countries, have followed 

 their example more closely than those of Britain. Ex- 

 tensive straight lines are doubtless irksome to the eye, 

 and do not suit the associations connected with the ever- 

 varying " line of beauty." But upon the king's high- 

 way, something is undoubtedly due to the ease of the 

 horse. There ought, therefore, in laying out a road, to 

 be a kind of compensating balance between the lines of 

 direction and draught ; and wherever weighty reasons 

 occur for varying the direct line, such as an acclivity 

 to be avoided, more proper soil to be obtained, the 

 avoiding of valuable property, or the including of a vil- 

 lage or town ; where such motives present themselves, 

 the judgment of the engineer will of course be exercised 

 in varying the line of direction. 



Line of One of the most important considerations in practice 

 draught, jg the adoption of a proper Line of draught, according 

 to the changing circumstances of the country through 

 which the road passes. Wherever a level line of road 

 can be obtained, it should in our opinion be adopted, 

 regard being had to the drainage of the soil, and the 

 particular form or curve given to the surface of the 

 road. In how very many instances does the scientific 

 engineer, when called on to improve a line of road, 

 carry us along a uniform and easy acclivity, instead of 

 an intermitting track, consisting of precipitous heights 

 or abrupt hollows. If, for example, we take the diffi- 

 cult pass of " Rest and be thankful," in Argyle- 

 shire, where the road is carried through the pass of 

 Glencrow, along an undulating line of draught, it 

 might, upon leaving Loch Long, be made to rise upon 

 a very gentle and uniform acclivity all the way, ad- 

 mitting, however, of occasional level parts for the re- 

 lief of the draught. In like manner, on the Loch Fyne 

 side, a much more easy line of draught than the pre- 

 sent might be fjound to the same summit. Similar in- 

 stances everywhere occur, in travelling over the chalk, 

 lime, and sandstone knolls of the south ; one or two 

 of these may also be noticed. On the great north road, 

 perhaps the worst stage between London and Inver- 

 ness is that between Newcastle and Durham, and here 

 the error might in a great measure be avoided, by 

 merely varying the line of direction. Another instance 

 is upon the great road from London to Ireland, through 

 South Wales by Milford. The stage alluded to is that 

 between Bristol and New-Passage ferry, which is ex- 

 tremely tortuous, both in its line of direciton and 

 draught ; although, by keeping along the right bank 

 of the Avon, the road might be shortened, and pre- 

 served nearly upon one level. 



Opinions We must not, however, omit to notice that various 

 about this, opinions exist with regard to the most proper line of 

 draught; some think that an undulating line is better 

 than one which is level. As this idea seems to strike 

 at the root of all our road improvements, it will 

 be proper to bestow more attention upon it, than 

 it would otherwise from its obvious nature seem to de- 

 serve. It is contended by many, that horses are more 

 fatigued with their load upon a level road, than upon 



one which goes up and down hill. This view is gene- .Roads and 

 rally supported by arguments supposed to be derived Highways, 

 from the anatomical structure of the horse, and from the ^"""Y""" 

 various muscles of the body being thus alternately 

 brought into action. But we may notice, that in an up- 

 hill draught, a carriage may be conceived as in the state 

 of being continually lifted by increments proportional 

 to its rise or progress upon the road, as already men- 

 tioned under the article RAILWAY. We may also show 

 this practically, as every one knows that on a stage of 

 twelve miles the post-boy generally saves, as it is term- 

 ed, at least half an hour upon the level road, because 

 on it he never requires to slacken his pace as in going 

 up-hill. Now, if he, or his company, would agree to 

 take the ame time to the level road that they are oblig- 

 ed to do upon the undulating one, the post-master 

 would find no difficulty in determining which side of 

 the argument was in favour of his cattle. With re- 

 gard to the fatigues or ease of the horse, the writer 

 of this article not having such plain matter-of-fact for 

 his guidance, upon one occasion submitted the sub- 

 ject to the consideration of a medical friend, (Dr. John 

 Barclay, of Edinburgh, no less eminent for his know- 

 ledge, than successful as a teacher of the science of 

 comparative anatomy,) when the Doctor made the fol- 

 lowing answer : 



" My acquaintance with the muscles by no means Dr. Bar- 

 enables me to explain how a horse should be more fa- clay's opi- 

 tigued by travelling on a road uniformly level, than by nion 

 travelling over a like space upon bne that crosses heights 

 and hollows ; but it is demonstrably a false idea, that 

 muscles can alternately rest and come into motion in 

 cases of this kind. The daily practice of ascending 

 heights, it has been said, gives the animal wind, and 

 enlarges his chest. It may also, with equal truth, be 

 affirmed, that many horses lose their wind under this 

 sort of training, and irrecoverably suffer from impru- 

 dent attempts to induce such a habit." In short, the 

 Doctor ascribes " much to prejudice originating with 

 the man, continually in quest of variety, rather than 

 the horse, who, consulting only his own ease, seems 

 quite unconscious of Hogarth's Line of Beauty." Re- 

 port on the Edinburgh Railway. 



Due regard having been paid to the lines of direc- Formation 

 tion and draught, the road comes to be formed perhaps and drain- 

 through an undulating tract of country, and over a va- a S e - 

 riety of soil, requiring different modes to be specified 

 for its execution. One ruling principle, which should 

 pervade the whole system of the formation of roads, 

 is their thorough drainage. The smaller drains, 

 connected immediately with the road, must vary in their 

 number, direction, and description, according to the 

 judgment of the engineer. They consist of what are 

 technically termed box and rumbling drains; the former 

 of which are built, and the latter consist of a stratum of 

 ruble stones, simply thrown into an excavation made for 

 their reception, through which the moisture is allowed 

 to percolate. Where the road is to be made through 

 a boggy or marshy soil, which is generally pretty level, 

 the opportunities for drainage are less obvious ; nor is 

 this so material, as ground of this description is capable 

 of containing a great quantity of water, without en- 

 dangering the flooding of the road. In such situations 

 it also fortunately happens that land is seldom of much 

 value, and therefore, in making a road through a mo- 

 rass, a much greater breadth should be included be- 

 tween the lateral drains than where the ground has an 

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