f>7-2 ON DRAUGHT. 



luiscliicf done "vvill, of course, be great in proportion to this curvature. 

 This form is, therefore, mischievous as well as useless. Six inches rise in 

 the centre of a road of twenty feet wide is more than sufficient to ensure 

 drainage, if drainage is not effectually prevented by ruts or hollow places, 

 and less than this will suffice where the road is good, and is kept in proper 

 order. 



The hardness of the surface, the most important feature, will of course 

 principally depend upon the materials used, and the formation of the road, 

 and still more upon the state of repair in which it is kept. It is easy to 

 form a good road when the foundation is already laid by the existence of 

 an old one : levelKng the surface — applying a covering of eight or ten 

 inches in tbickness of broken stones — having as few round or smooth 

 surfaces as possible, the hardest that can be obtained — and above all 

 things secui'ing good drainage, both from the surface and from the bottom 

 — is all that is required ; but constant repair and unremitting attention are 

 necessary to keep a road thus formed in good condition. 



These repairs and attention do not consist in laying on at certain 

 intervals of time large quantities of materials, but in constantly removing 

 the sand which is formed, and which, in wet weather, holds the water, and 

 ])revents drainage; in filling up as quickly as possible, with fresh ma- 

 terials, any ruts or holloAvs ; and particularly in keeping clear all the 

 drains, and even in scraping small drains from ruts, or such parts of the 

 road as may contain the water, and which it may not be possible imme- 

 diately to fill up. 



By attention to these points, those who are interested in the preservation 

 of the roads, and the expenses attending it, Avill find that economy will 

 ultimately be the result ; and those who are interested in diminishing the 

 labour and expense of draught, we shall only refer again to the table 

 (page 558) of the resistances of a waggon upon different roads, from which 

 they will see that a horse upon a clean road will do one-third more than 

 upon one shghtly muddy, more than four times as much as upon new-laid 

 gravel, and nearly seven times as much as upon a heavy sandy road. 



No arguments that we can put forward can at all strengthen the effect 

 that such facts must produce ; and we shall, therefore, quit the subject of 

 roads, and conclude our observations on draught by a few words ex- 

 planatory of the object of railroads, and their effects as regards diminishing 

 draught. 



The great desideratum in the formation of a good road is the facilitating 

 the rolling of the wheels. We have shoTv^^ that, for this purpose, a hard, 

 smooth surface is necessary ; and, as this is only required for the wheels, 

 two longitudinal tracks, of such surface, of proper "width, are sufficient for 

 the mere passage of the carriage. If, therefore, thei-e is a considerable 

 traffic between two points along a line of road, without much inteiTuption 

 from crossing, all the qualities of a good road may be obtained in a very 

 superior degree, by having two parallel rails, or tracks of wood or iron, 

 raised a little above the general level of the ground. This is a railroad. 

 It evidently affords the means of attaining any degi^ee of perfection in those 

 essentials for a good road — hardness and smoothness of surface for the 

 wheels to roll upon. It requires, however, that the carnages should be all 

 nearly alike, as regards the width and form of the wheels ; and experience 

 has proved that such a road is not generally worth constructing, unless the 

 traffic is sufficient to allow of carriages being built expressly for that or 

 similar roads. This being the case, the form and dimensions of the rails, 

 and the general construction of the carriages, are uncontrolled by any 

 other consideration than tliat of dimiuishino- drauri^ht. 



A considerable improvement upon this point may, therefore, be ex- 



