Nelson's history of the war. Vol. XI., The struggle for the Dvina, and the great invasion of Serbia

THE OVERRUNNING OF SERBIA. 149

fAanked and isolated it on the south. For this purpose he must secure the railway, if possible, as far as Veles. The line, a single grass-grown track which followed the windings of the Vardar, showed one point of especial danger. Ninety miles from Salonika, north of Strumnitza station, the Vardar flows through a narrow gorge, called Demir Kapu, or the Iron Gate. At the mouth of the pass the railway crosses to the left bank of the river, and follows it on that side through the ravine, returning to the right bank, where the valley widens out beyond the narrows. The Iron Gate thus involved two bridges, a tunnel a hundred yards long, and ten miles where there was no space to spare between the river, the railway, and the precipitous walls. If the Bulgarians seized this point all access from the south into Central Macedonia was barred. Bulgarian raiders had early in the month cut the railway at Strumnitza station, which was six miles from the frontier, and about twenty-five from the Bulgarian town of that name. On 19th October the French advanced guards el 19: reached the place, and drove out the enemy. Four days later, on 23rd October, the rest of the division began to arrive, and detach- 21.23, ments were ferried across the swollen Vardar, and seized positions on the left bank. On 27th October the French occupied Krivolak without difficulty, and pushed posts farther up the line towards Gradsko. Sarrail now held a position from north of Krivolak to south of Strumnitza station, while the British 1oth Division extended on the French right to Lake Doiran, to

Oct. li27.