Brig. Gen. Charles Gratiot,
Chief Engineer.
Baltimore, May 6, 1833.
Sir: The instructions of the department of the 23d July last, relating to the method of repairing the Cumberland Road east of the Ohio, are founded upon principles upon which I differ in opinion, and beg leave to request your reconsideration, involving, as they do, an expenditure of not less than $250,000, when compared with what I judge to be the most judicious method of making the repairs.
It is in relation to the propriety of breaking up the old bed of the road in all cases. I apprehend the department was not aware that the bed is a substantial, yet rough pavement, and not formed of loose, detached masses of quarry stone thrown together, without order. It is important to consider this particular when examining the authorities on road making.
My own views are that it is decidedly preferable to retain the old pavement in all cases where its continuity is unbroken, even mending small parts that may be deranged, and Macadamizing over it. In this, I think, I am borne out by Macadam, Dean, Telford, and Farey, whose ideas on the subject are annexed, as extracted from “Macadam on Roads.”
The only two arguments against the method I propose are, first, that the metal will grind to dust by being placed over large stone. In answer to which, I say, that the road passing through a rocky country, even after removing the pavement, there still remains a rocky foundation; and where the pavement is well bedded in sand or clay, we have all the elasticity necessary from the clay or sand bed through the pavement. In support of which, see the sample of metal taken from the road through Uniontown, where the under strata have not worn or crushed an iota, presenting angles as sharp as the day they were first placed there. Were the metal placed upon an unyielding rock, it would doubtless soon grind to dust; but placing it upon a pavement laid in sand or gravel, preserves the elasticity so necessary for this kind of road. Second: That large stone, placed under Macadam metal, will work to the surface. This is doubtless true when detached pieces are surrounded by the metal, but with a pavement the case is very different. I find pieces of this Cumberland Road, repaired as far back as 1827, by Mr. Ewing, over the old pavement, in perfect order to this day; as, also, some parts done in this way by Giesey in 1829, that are much better than any of the repairs he made at the same time; and a piece through Uniontown, by the authorities of the place, in 1830, remains in perfect order.
I have been led to reflect upon this subject from learning that the Ohio road had cut through and was impassable at certain places during the months of February and March, and seeing the state of the road under my supervision between Cumberland and Wheeling, comparing the parts repaired last season, those under Giesey, Ewing, and the town authorities, with the old pavement that has stood sixteen years without a cent of money in repair, and to this day is a very good wagon road, rough, it is true, yet never cutting through during the fall, winter, or spring, where the pavement is continuous. To throw away so firm a foundation I cannot think advisable, and beg you to reflect upon the subject and favor me with your views.
The road in Ohio has worn six years (nearly) without repairs, and was impassable this spring. The old Cumberland Road has worn sixteen years, and mile after mile has never been known to cut through at any season. Parts of it covered with Macadamized metal, and worn for five years, are in fine order, and present a very smooth surface, never having cut through. Other parts, where the old pavement has been removed and Macadamized, were impassable during the spring after three years’ wear. We have to bear in mind the impossibility of keeping the ditches and drains open in the mountains during the winter. Ice forming in the drains will, of course, throw the melting snows on the surface of the road, which is destructive to a Macadamized road on clay or sand, whereas, if on the old pavement, it has strength enough to resist the travel until either dried by frost, or sun. This is a consideration that the English road-makers had not to consider with the same weight. As to keeping the drains open, and the road surface free from water in the winter, I conceive it impracticable in the mountains; hence the further propriety of preserving a foundation that will secure a firm road at all seasons, even if the wear should prove some five or ten per cent. more rapid, which I do not even think will be the case on the plan suggested of Macadamizing upon a pavement, and not on an unyielding, rocky bottom.
Respectfully, your obedient servant,
RICHARD DELAFIELD,
Captain of Engineers.