The waves were the commandos of the district, most of which had retired under C. Botha from the Laing's Nek positions. Buller had not much difficulty in dealing with them as obstructions to his advance, and in succession he occupied Amersfort, Ermelo, and Carolina; but they soon returned to their stations. His own inclinations would probably have persuaded him to halt and smash them, but he was marching against time between two widely separated bases. Near Carolina on August 14 he came in touch with French, who was acting with Lord Roberts' eastward movement from Pretoria, and from that date the operations of the Natal Army were merged in those of the main Army, and came under the immediate direction of the Commander-in-Chief. A scheme proposed by French and sanctioned in substance by Lord Roberts, for an immediate cavalry turning movement round the left flank of the enemy, who was strongly posted astride the railway near Belfast; in conjunction with a central infantry advance to be made by Buller and Pole-Carew, whose Division was within reach, was discountenanced by Buller, and a simple frontal movement was substituted for it. Its practicability was doubtful owing to the marshy character of the ground. On August 25 Buller, French, and Pole-Carew entered Belfast, where they were joined by Lord Roberts. Notes: [Footnote 48: i.e. the section of the railway from Johannesburg to Natal which is in the Transvaal.] CHAPTER XIV The Taming of the Transvaal The course of the war north of the Vaal after the battle of Diamond Hill up to the date of Lord Roberts' arrival at Belfast seven weeks later was tortuous and difficult. The main Army changed front as soon as Pretoria was reached and faced to the east in the direction of the retreating Transvaal Government. Its line of communication became a prolongation of its front; its left flank towards the north was open; and on its rear was the unsubdued country west of the capital in the direction of Mafeking and Vryburg. Through this district, which is intersected by ranges running generally east and west, and which contains some towns of importance, the troops set free by the relief of Mafeking advanced in two columns towards Pretoria and Johannesburg. The southern column was Hunter's Xth Division, which after easily occupying Potchefstroom and Krugersdorp, passed through Johannesburg, and on Hunter's being sent into the Free State was broken up at Heidelberg. The northern column, under Baden-Powell, occupied Rustenburg and met with little opposition during the month of June. It was intended by Lord Roberts, if all went well, that this column should eventually take up a position on the Pietersburg railway, north of Pretoria, which was unprotected in that direction.