Experiments in Draught.

Manawatu Herald, 23 September 1893, Page 3

Experiments in Draught.

An American professor (writes a contributor in a contemporary) has been making experiments to ascertain what the difference is between the force required for pulling a load of given weight over different kinds of roacfe, and to show the value of broad tires.) The wheel tires were respectively l_4n. and Sin. wide, on a partially dried mud road. The load in each case was 3>0951b The draught for the broad tires 8711 b., and for the narrow 4411 b., and the broad tires cut the road less deeply than the narrow ones. In the case of our gravel or stone roads the good effect of broad tires would probably be more noticeable on mud roads. Most European countries have laws regulating the width of tires on vehicles. In France the market waggons have tires from Sin. to lOin. in width, usually from 4in. to Gin. Not only have they wide tires, but in most of their four-wheeled waggons the rear axle is longer than the fore axle, so that the rear wheels run on a line about an inch outside of the line of the fore wheels ; instead of being a road-destroyer they are a veritable road-maker. In order to encourage the use of wide tires in some States of America, there is a law granting a certain reduction in taxes to those who use broad tires. Vehicles on springs are much easier on roads than vehicles without springs, and wheels of large diameter do less damage than smaller ones, and cause less arau^ht.