CHAPTER XI.

TURNPIKE ROADS.

THE resistance of carriages upon turnpike or common roads has, of late years, been very much diminished, by covering the surface with materials broken into smaller pieces than formerly, thereby forming a much smoother surface; and experience has shewn that such a surface is much more easily kept in repair, than the rough uneven roads previously in existence. The public are indebted to Mr. McAdam, for the introduction of this system, of breaking the stones smaller than they had previously been done; but the late Mr. Telford, who was engineer to government, in forming and improving the Holyhead line of road, has contributed more largely than any other person to our stock of information on road making, and the principles requisite for their construction, and which may be all summed up in one simple rule, viz. "that a good foundation is the first requisite."

It is not, however, our intention to enter into either the principles or practice of road making; the reader, who is desirous of doing so, will obtain all the requisite information by consulting Sir H. Parnell's work on this particular subject, and the reports of Mr. Telford on the Holyhead line of road. Our object being, to present to the reader such facts, as will shew the resistance of the carriages, and cost of conveyance upon turnpike roads; and to compare their capabilities, with other modes of internal communication.

§ 1.--Experiments on the Resistance of Turnpike Roads.

We shall, therefore, at once, proceed to give the result of some experiments made to ascertain the resistance upon turnpike roads, extracted from the reports of the Holyhead Road Commissioners.

The following table, shewing the number of pounds requisite to drag a waggon of the weight of 21 cwt. 8 lbs. at the rate of two miles and a half an hour, has been extracted from the Seventh Report of the Holyhead Road Commissioners.

No. 4.