A railway from Fratesti to Simnitza had become indispensable inasmuch as the main line of communication for the Russian Army could not be continued for an indefinite period along the forty miles of defective roads--speedily worn out by the heavy traffic--which separated the Bucharest-Giurgevo line from the bridge built across the Danube. The only important earthwork necessary was an embankment a mile and a half long and fourteen feet high. The bridges to be provided included one of 420 feet and two of 210 feet each. In this instance the troubles experienced were due to the difficulty in getting the necessary materials for the work of construction owing partly to the existing Rumanian lines being blocked with military traffic, and partly to the state of the roads and to the use of all available draught horses for Army transport purposes. There could thus be no great celerity shown in construction, and the forty miles of railway, begun in the middle of September, were, in fact, not ready for working until the beginning of December. Like difficulties were experienced, though to a still more acute degree, in regard to the Sistova-Tirnova line, the length of which was to be seventy-five miles; and here only the earthworks could be finished before the end of the campaign. What, however, had been accomplished during the time the war was in progress was (1) the completion of 229 miles of new railway, and the making of the road-bed for another seventy-five miles, together with the carrying out of a number of minor railway works; (2) the acquisition, by purchase in different countries, of 120 locomotives and 2,150 wagons and trucks, all new, and (3) the provision of a steam railway ferry across the Danube.[38] So the development of the rail-power principle in warfare was carried still further by this construction, during the course of the Russo-Turkish conflict, of a greater length of railways, designed for military use, than had ever been built under like conditions before. The world gained a fresh lesson as to the importance of the rôle played by railways in war, and it was offered, also, a striking example of what could be done in the way of rapidly providing them in a time of emergency. On the other hand it had to be remembered that, of the three railways in question, the one which included 189 miles out of the total 229 miles built was constructed on Russian territory where there was no danger of interruption by the enemy, while the delays which occurred with the two other lines, owing to the congestion of traffic, under war conditions, on existing railways depended upon for the supply of materials, seemed to point (1) to the risk that might, from this cause, be run if the building of lines necessary or desirable in the interests of some prospective campaign were left until the outbreak of hostilities, and (2) to the wisdom of constructing all such lines, as far as necessary and practicable, in time of peace. THE SUDAN