606 PRACTICE OF AGRICULTURE. Part III. 



3733. Farey finds the Whitechapel road more injured by broad wheels than any other, 

 owing to these wheels being barrelled and conical, and not running flat, and the middle 

 tier projecting above the others, with rough nails. 



3734. Cumming has proved experimentally before the committee of 1808, that when 

 the rim of a wheel is made truly cylindrical, so as to have an equal bearing on its whole 

 breadth, the resistance to its progress on a smooth road is not increased by increasing its 

 breadth. With regard to the immense saving that would accrue to the nation, Jessop, 

 in his report, says, " I may venture to assert, that by the exclusive adoption of cylin- 

 drical broad wheels and flat roads, there would be a saving of one horse in four, of 

 s6venty-five per cent, in repairs of roads, fifty per cent, in the wear of tire ; and that the 

 wheels with spokes alternately inclined would be equally strong with conical ones, and 

 wear twice as long as wheels do now on the present roads." But, over and above the 

 preference due to such wheels, in respect of public roads, they are no less preferable when 

 applied to purposes of husbandry. Besides the great resistance to the draught occasioned 

 by the sinking of the narrow wheels on soft land, every farmer knows what injury is fre- 

 quently done to subsequent crops by such poaching and cutting up of the land. But 

 this is not all. Many a field of beautiful pasture, when subjected to the destroying 

 operation of the narrow wheels, is very much injured, both in respect of the appearance 

 and of the crop, which would be entirely prevented by using broad wheels. Thus it has 

 been stated, with regard to the introduction of the use of broad wheels, that the saving 

 on the incidental repairs of the road would be immense ; that the roads would uniformly 

 retain a smooth and even surface, which would greatly contribute to the comfort of the 

 traveller and the ease of the draught; that in husbandry also the advantages would be great ; 

 in short, that, in every point of view, the benefits which would be derived in consequence 

 would be paramount to every thing that could be urged in favour of the narrow wheels. 



3735. M^Adam thinks a waggon wheel of six inches in breadth, if standing fairly on 

 the road with any weight whatever, would do very little material injury to a road well 

 made, and perfectly smooth. The injury done to roads is by these immense weights 

 striking against materials ; and, in the present mode of shaping the wheels, they drive the 

 materials before them, instead of passing over them. If a carriage passes fairly over a 

 smooth surface, he says, it cannot hurt the road, but must rather be an advantage to it, 

 upon the principle of the roller. On being asked, " Are you not of opinion that the 

 immense weights carried by the broad-wheeled waggons, even by their perpendicular 

 pressure, do injury by crushing the materials?" he answered, " On a new-made road the 

 crush would do mischief, but on a consolidated old road the mere perpendicular pressure 

 does not do any. But there is a great deal of injury done by the conical form of the 

 broad wheels, which operate like sledging instead of turning fairly. There is a sixteen- 

 inch wheel waggon, which comes out of Bristol, that does more injury to our roads, than 

 all the travelling of the day besides." 



3736. With regard to regii/ating the weight to be carried on wheels, Farey judiciously 

 observes, that though it is not easy to state any one scale which would be generally appli- 

 cable for each breadth of wheels below six inches, there should be a rate fixed, which 

 would apply to ordinary or gate tolls ; and at the weighing machines additional or what 

 may be called machine tolls should be levied upon all carriages which exceeded the 

 weight, to be regulated in an increasing scale for each breadth of wheel, so as very greatly 

 to discourage, but not ruinously to prohibit the occasional carrying of large weights upon 

 any wheels. 



3737. Axletrees of different lengths have been proposed by some engineers with a view 

 to preserving the roads. On this subject Paterson observes, " At present the axles of 

 all kinds of carriages are made to one length, so that their wheels all run at the same 

 width, and in the same track, than which nothing could be more fitly devised for the 

 destruction of the roads. I would, therefore, propose, that the length of the axletrees 

 should be so varied, that the wheels of the lighter description of carriages should run 

 two inches narrower than the present track ; and that the axles for the more ^'eighty 

 carriages should be increased in length, so that their wheels should run from one to four 

 inches beyond the present track. I would also propose, that mails, and other heavy 

 coaches, should be so constructed, that the hind wheels should follow, either two inches 

 within, or two inches outside, the track of the fore wheels, as might be considered most 

 proper. Were the axletrees of all kinds of carriages to be of various lengths, as here 

 proposed, we should have no rutted roads. The stones now displaced by the wheels of 

 one carriage, would be replaced again by the next carriage that came up, having its axle 

 of a different length ; and in the same manner would the hind wheels repair the injury 

 done by the fore wheels of a carriage. If this plan were to be acted upon all over the 

 kingdom, it is evident that it would have a very beneficial effect on the roads ; and if it 

 should be found thus to contribute to keeping the roads smooth and even, it is also 

 evident that it must contribute, in the same proportion, to the comfort of travellers of 

 very description, and also to the ease of the beast of draught." 



