Roads . 
289 
firmly fixed on the upper. It would be certainly a more rational 
construction to build up the shoulders of the road firmly with 
large stones rather higher than the road itself, and then to fill in 
perfectly level across with equal small stones. A road so con- 
structed would retain its materials much better and longer than 
the other, especially if care were taken, to prevent as much as 
possible a very rapid discharge of the rain water from it. 
4. Contiguous to the pavement there is to be a ditch. This 
ditch must be certainly intended to catch the water coming down 
from the sides of the mountain, on the slope of which the road is 
made. To get into the ditch then, the water must pass over 4 or 
5~ feet of unpaved soil, the pavement being directed to be made hi 
the centre of the 30 feet, which are to be levelled. I have under- 
stood, that the road continues in many parts upon one uninterrupt- 
ed ascent of a mile and upwards. If this inclination should be of 
four and a half degrees and regular , it may easily be imagined, 
what will be the effect of a current of water running over the soft 
soil for a mile, and not only increasing as it descends in velocity, 
but also in volume. The bottom of the ditch would soon assume 
the parabolic line which the slope of all mountains acquire from the 
wash of rain water ; and the pavement would gradually be under- 
mined and tumble into it. But I presume that there will be as 
usual, stops thrown up to guide the current across the road at pro- 
per distances, which, although not provided for in the contracts, is 
so far a practical remedy for the evil. But it must, even if this 
be done, be apprehended, that in time a gully will be formed on. 
the upper side of the road ; and this gully will take place on thd 
soil between the ditch and the hill, making the whole of the up* 
per unpaved level one irregular ditch. 
Having thus objected to the Avhole construction of the road, 
you have a right to expect, that I should point out, what, in my 
opinion, it ought to be. This I will not hesitate to do, with the 
most perfect candour and freedom. 
1 . The road being cleared 30 feet in width, the upper bound- 
ary of the road should be so laid, as that the earth to be cut from 
the slope of the hill will be sufficient to raise the lower or forced 
side higher than the other ; the surface inclining towards the hill 
about 1 foot six inches. The made ground will settle so as to 
become perhaps nearly level, but it should always be rather high- 
er than the opposite side to prevent the water from running across 
the road. The cut on the hill side Should be, in general, per- 
Voi. III. O o 
