42

HISTORY AND PROGRESS

or about 42 cwt. was the universal load attachedto a horse, and the road was levelled accord-ingly, the only desideratum being to enable ahorse to convey that quantity.

In some parts of the road, where occasionalacclivities occurred which could not be levelled,or where sudden windings of the road wereobliged to be made, thin plates of wrought ironwere laid upon the surface of the Rails, andfastened down with common nails, to diminishthe resistance opposed to the wheels, and equa-lize the draught of the horse. This, no doubt,would be found a great improvement, not onlyin diminishing the friction, but also in pre-venting the Rails from wearing. Yet I donot find the use of them much extendedbeyond the above-named instances ; proba-bly, from the difficulty of keeping the platesfast upon the Rails, as the nails, by theelasticity of the wood, would be constantlyworking loose, and occasioning a continualexpence in keeping them right. Upon thewhole, however, the use of such plates would,in many cases, be attended with considerablebenefit, and might, had they not been super-seded by the introduction of a different kindof road, have been much improved.

About this period, in all the extensive miningdistricts, we find canals the only system of internal