ROAD. 



comprehended all the requifites neceflary to form a complete formed, mull be allowed to harden and k-ttle for iome time 

 road. To attain them in the beft manner is therefore the before any other materials are laid on, great care being taken 

 important point. Four different methods have been dated, while in that Itate, to let no carriages or cattle upon it and 

 each of which has its fupporters. The arguments in favour it (hould be rolled with a long wooden roller, that will reach 

 of each have alfo been fhortlv mentioned, which will fhew at once from each of the fides to the middle. This roller 

 that their main obje& is the fame, unlefs perhaps the idea (hould be loaded with a box of Hones to make it fufheientlv 

 of watering the concave road may be confidered a deviation heavy, and that it may be the more portable when that box 

 trom one part of the general rule; but as that is propofed is taken off; and it maybe fo contrived, that by chane-iiif 

 to be done only to wafh the road occalionally, in cafe it be- the horfes from one fide to the other, there will be no occa- 

 comes dirty or fiufhy, it cannot therefore be confidered in fion to turn the roller, in order to make it roll the fame 

 that light in any refpect whatever. But from thefe modes fpace over again. Being rolled in this manner, will confo- 

 of conflru&ing roads being in fome meafure unfatisfactory, lidate the materials compofmg the ridge of road, and pre- 

 he is induced to offer a new theory on the fubject, which is pare it for receiving thofe to come afterwards, for it is a molt 

 founded on the knowledge of the dratiiied nature of the abfurd practice to lay hard materials in the common way 

 .■arth. [t is however only given as theory, having never, upon this firlt form or bafis of a road, before it is fufficiently 

 he believes, been fubjected to the telt of actual practice, firm to bear them. When thus formed and properly fettled 

 It is obferved, that every perfon who has paid the lead at- the next itep to be taken is to imitate the works of nature 

 tention to the drueture and formation of the different ftrata in dry foils as nearly as poflible, by forming a flratum 

 of the earth, mull have feen that fome of thefe llrata are of penetrable by water, compofed either of fand or fandy 

 io clofe a texture as to be impenetrable to moifture ; others gravel, or any other fubdance eafielt to be got, that is fuf- 

 again are fo porous, that water will eafily run through them ficiently porous to admit water to pafs through it. This 

 in any direction, till it meets with fome obltacle, or finds a Itratum (hould be laid quite level, and extending from one 

 vent. Of the firft fort fome are lefs denfe, and of the latter fide of the road to the other, filling up the fmall drains alfo 

 iome lefs porous than others, confequently as they partake on the fides. Over this are to be laid the belt materials that 

 more or lefs of thefe qualities, the water or moiiture will can be got for completing the road, confiding either of 

 the more or lefs quickly penetrate through them. But in dones broken very fmall, or of the bed gravel. This coat 

 order to fhew this more clearly, and apply the principle to of hard materials need not exceed above fix or feven inches 

 the conltruction of roads, he fuppofes the fection of a hill in thicknefs, which being much lefs than is commonly ufed 

 or eminence compofed of a number of ftrata. It the upper will be a confiderable faving ; and it may even Hill be lefs 

 itratum or furface foil is of a porous nature, it is evident if the directions hereafter given are ftrictly attended to. 

 that any water which falls upon it, will penetrate through If this covering confilts of broken ftones, they mould af- 

 to the flratum below, where, if it cannot go farther, it will terwards be laid over with fand or fine gravel, when eafily 

 glide along the furface till it finds a vent at the bottom of procured, fo as to fill up all the cavities betwixt them, 

 the hill ; if the fecond itratum is hollow, and continues on The fand or rubbifh from a freedone quarry is excellent 

 towards any depreffion in it, the water will lodge in that tor this purpofe, providing there is no mixture of earth in it 

 hollow, and form a fort of pool or bog, as is fometimes which fhould be carefully guarded againd in every dep 

 obferved on the tops of hills ; but if in this hollow place taken after the road is fird formed. Thefe finifhing mate- 

 there is a communication wi;h the porous itratum, no water rials being properly laid on and fmoothed with a rake the 

 will lodge there, but it will penetrate through and glide whole (hould now, before any carriages or horfes are admitted 

 >ng the upper part of the denfe itratum below, till it finds upon it, be well rolled with a heavy iron roller, divided in 

 a vent on the fide or at the bottom of the hill, as before, three parts for the purpofe, the two hind divifions of the 

 \nd by tin- above it will alfo appear, that if the uppcrmoft roller being large, the front or middle divifion fmaller, to the 

 ilratum is of a clofe texture or clay, any water falling framing of which the (hafts are fixed, and fo contrived, that 

 upon it will not only lodge in the large hollow, but in the it turns in the manner of the fore-wheels of a waggon * 

 fmaller ones, and in all the other irregularities or concavities there is a box for holding dones to increafe the weight when 

 that may happen to be upon the furface. Hence, alfo, it neceflary ; but in adding this weight, it mud be obferved 

 is evident that in order to keep dry the furface of any fuch to lay about two-thirds of it over the two large parts, and 

 piece of ground, it matters not of what lhapc or form that only one-third over the other, otherwife the preifure will 

 furface is, or whether it is convex or flat, provided there not be equal. Iron rollers are fometimes made in three 

 is a communication with fome under dratum, fufficiently parts, as above, but being all in a line, and clofe together 

 porous to carry oft" the water below ; but it is of fome con- they are apt to be choaked by gravel and fmall dones, which 

 lequence the for>n of the upper part of that itratum upon cannot happen in the conftruction here recommended. It is 

 winch the water is to run, tor the fmoothtr it is, the contended, that if fuch a roller were generally ufed upon 

 water will of courfe the more eafily flow away, and be dii- roads, efpccially when newly made, it would fave a great 

 charged from it. deal of expence in repairing them ; for it cannot be expected 



It is eafy, it is fuppofed, to apply thefe principles in the that any new road will immediately bear wheel-carriages, or 

 forming of roads in the following way : when a new road is continue long in repair, when compofed entirely of loofe mate- 

 to be formed, let it be done in the lirll inilance nearly in rials, without the (mailed pains being taken to confolidate 

 the ulual manner, witli fuch materials as are on the fpot, and them together. Frequent and heavy rolling would therefore 

 'rcr the quality of thefe approaches to clay, fo much produce the mod beneficial effects, and would tend very much 

 the better. Indead, however, of forming it convex, as is to keep the road free from deep ruts and holes; belides, 

 generally done, let the lines on either fide from the middle there 'is nothing could contribute more effectually to pro- 

 be quite ftraight, and meet in an angle or ridge at that part mote and preferve firmnefs and folidity, two qualities with- 

 or the middle of the road, having a (lope trom thence to out which it is impollible anyroad can, with propriety, be 

 each fide, of about an inch in a foot. There are to be made called a good one, or have the neceflary degree of folidity 

 fmall drains for the more eafily conducting away the water and tirmnefs. 

 that may be collected at thofe places. The road, being thus The advantages that would relult from this mode of con- 



flict 



ion 



