Now appeared an unexpected difficulty. The Roman cistern at the top of the Medean pass, which it had been hoped would provide water for the whole column, proved to be dry, as were the wells at Siwiat further along the ridge. This compelled General Peyton to revise his plan. Clearly, he could not send the second column by the same route as the first; indeed, the water supply made it impossible for the first column in its entirety to continue on its original line. He therefore made a new disposition of his forces. Lukin was ordered to push along the top of the escarpment with the 1st and 4th South Africans, the armoured cars, the Hong-Kong and Singapore Battery, and a company of the Australian Camel Corps. The rest of the infantry and the mounted troops were directed to proceed from Augerin along the coast to the foot of the Halfaia pass. Lukin’s force carried their water in “fantasies” on camels, and their total supply, which had to last for forty-eight hours, was limited to eight pints per man. [Sidenote: _Mar. 15._] The movement began on the 13th. At midnight Lukin was four miles from the Halfaia, the rest of the infantry at Alim Tejdid, and the cavalry at Bagbag. At daybreak on the 14th the armoured cars moved forward to the Halfaia pass, which they occupied without opposition. At 9 a.m. we learned that the enemy had evacuated Sollum the previous evening and was retiring to the south-west. There was now no obstacle in front of the two columns, and the mounted troops joined Lukin on the high ground. Next day, 15th March, General Peyton entered Sollum.