ON DRAUGHT. 4&1 



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 prevents drainage ; in filling up as quickly as possible, with fresh 

 materials, any ruts or hollows ; and in keeping clear all the drains, and 

 even in scraping little drains from ruts, or such parts of the road as may 

 contain the water, and which it may not be possible immediately to fill up. 



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

 of the roads, and the expenses attending it, will 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 30) 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 slightly 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 observntions on draught by a few words explana- 

 tory of the object of rail-roads 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 shown 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, there is a considerable traffic 

 between two points along a line of road, without much interruption from 

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

 degree, by having two parallel rails, or tracts of wood or iron, raised a little 

 above the general level of the ground, with a gravelled road between the 

 rails. This is a rail-road. It evidently combines the advantages of a good 

 foot-hold for horses, with those of smooth and hard surfaces for the wheels 

 to roll upon. It requires, hov/ever, that the carriages 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 con- 

 sideration than that of diminishing draught. 



A considerable improvement upon this point may, therefore, be expected 

 in the railway over the common road. The railway, as constructed upon 

 the plan at present conceived to be the best, consists of two parallel bars 

 of wrought iron, about two inches and a half broad on the upper surface, 

 and about six inches deep, placed at a distance of about five feet : these 

 bars are supported upon, and firmly fixed to blocks of stone, from one 

 foot to two feet square, and at intervals of three feet. 



a a a, fig. 40, represents a side view of one of these bars, of which 6 is a 

 section, c c c are the blocks of stone on which it rests. Fig. 42 is a per- 

 spective view of a pair of these parallel bars, constituting together the 



Fig. 40. 



(I a ^ . 



c 

 2 G 2 



