402 Report on the Exhibition of Implements 
dowmvard slope ; the axles, therefore, which bear the whole 
weight of the cart, rest upon sloping bushes, or, in other words, 
upon inclined planes, and the result of a weight so applied is 
that a lateral as well as a vertical pressure is produced, causing, 
wherever the road is at all uneven, a jerking motion from side to 
side, which adds greatly to the friction on the shoulder of the 
axle and the linch-pin. 
The defects of the conical rim are equally great, as the natural 
tendency of a wheel of this shape when rolled on its edge is to 
revolve round its vertex, and if constrained to move in a straight 
path it is partly rolled and partly dragged along the road. Wheel- 
wrights are so well aware of this tendency that they endeavour to 
counteract it by making the wheels look inwards, {. e., placing them 
so that they are nearer to one another in front than behind ; and no 
doubt this is of use under the circumstances, but it is at best only 
a makeshift by which an error in one direction is made to counteract 
in some measure another of an opposite tendency. Few people 
ai-e aware of the additional and very unequal pressure that is in this 
way thrown upon the axles^ and any one who is interested in the 
subject may readily test it for himself by removing a wheel from 
the cart and placing one end of a small crowbar or strong walking- 
stick in the bush of the wheel, the other end being held in the 
hand. When the wheel is upright no force is required to keep 
it so, but if it be placed in a position leaning from the holder of 
the stick he will find that a heavy wheel will require a strong 
effort with both hands to prevent it from falling. This represents 
the extra weight thrown on the axle in consequence of having the 
wheels in a leaning position. Next, let the wheel be rolled on 
its edge, whilst the experimenter walks forward in a straight line, 
and he will find himself sorely puzzled to prevent the wheel from 
turning away from hira by any effort which he can make with 
his stick, and will thus become practically convinced of the 
unequal pressure and unsteady action of conical wheels, which in 
fact are fitted to move only in one direction, but are continually 
dragged and forced to move in another, producing a great increase 
of friction and additional wear and tear of material. 
To avoid these evils the axles should be very nearly straight, 
and the wheels consequently very nearly upright. The reason 
why the former should not be quite straight and the latter 
quite upright is, that for convenience in greasing, &c., it is uni- 
versally the practice to make the axles taper towards the end ; 
if therefore the axles were put on quite straight, their taper- 
ing form would cause them to rise towards their extremities, 
which would produce, though in a slighter degree, the evils 
before described as resulting from sloping bushes, the slope in 
this instance being towards the cart instead of from it. It is very 
