Under whatever system of haulage the acceleration of trains be obtained, the increased speed will call for increased precautions in the selection and proving of the materials to be used in such service. Rails must be made more uniform in quality, and must be free from the imputation of fracture under regular wear. Notwithstanding the great improvements made in the preparation of the steel, and in the rolling, there are still far too many steel rails which break under traffic to allow rail-makers to rest satisfied with their work. Something is still wanting in the manufacture to effectually remove this disposition to fracture. The safe rail, the rail of the future, must be one that may bend and may wear, but will never break under ordinary use in the road. Axles must be stronger and tougher, as they will have to bear greater torsional strains than are now imposed upon them; and the wheels, of whatever type they are made, must be incapable of collapsing or falling to pieces upon the sudden and severe application of the brake-blocks. A train, rushing along at a speed of 70 or 80 miles an hour, may on an emergency have to be brought to a stand in the shortest distance possible, and the failure of either axles or wheels in the endeavour to avert one form of accident would inevitably initiate another. To permit of unchecked high-speed running, many sharp curves will have to be flattened, bridges will have to be built at busy level crossings; and points, crossings, and junctions on the main lines will 358 have to be reduced to the smallest possible number.