such a system would be, will scarcely wish for its return; it would be indeed a lamentable retrogression, injurious alike to the public and the railway companies.[6] [6] See the unqualified condemnation of the system in the Italian Parliamentary Report already quoted: “The natural system was a system eminently theoretical. To-day all doubt on the subject is removed; this system was tried for five years, and it proved very unsatisfactory.” Parte II., Vol. III., p. 954. It is pointed out with truth that the so-called “natural system” is injurious to small industries and small towns. See also page 18. SECTION IV. EQUAL MILEAGE RATES. Another proposal which, though always condemned by competent judges, is still, in some form, very often brought forward, is to charge equal mileage rates.[7] Admitting the impossibility or impropriety of making rates vary according to the cost of conveyance of goods without reference to their value or quality--recognising the expediency of classification in some form--many persons think that it would be well to charge for the same kind of goods the same sum per mile universally. This plan is simple; it has an appearance of being equitable; and, as such, it is attractive. But, on the slightest consideration, it becomes apparent that exceptions which mar this simplicity must be admitted. In fact, no one proposes that this principle should be inflexibly carried out. Far from being really equitable, equal mileage rates would often act most unfairly. Mileage run is only one element out of many in cost of service; and to compel companies to charge the same sum between points equally distant, irrespective of the original cost of constructing the way, the nature of the gradients, the amount and regularity of the traffic to and fro, and the extent of back haulage of “empties,” would be doing great injustice. Obviously an allowance must be made to cover the cost of specially expensive undertakings, such as the Runcorn, Tay and Forth Bridges, the Sol way Viaduct, or the Severn Tunnel. So, too, allowance must be made for steep gradients; manifestly the same paying load cannot be carried over gradients of one in forty as over one in eight hundred. In Germany and Holland an effort has been made to adopt the mileage system; and (subject to exceptions for import, export and transit rates, referred to afterwards) it is assumed to be carried out. But patent facts could not be ignored; in these countries an extra mileage up to 12 kilometres (about 7½ miles) is taken into the calculation of rates for expensive bridges and steep gradients. Speed, too, must be taken into account; as it increases, a more than proportionate increase in engine power is necessary.[8]