On February 11 Lord Roberts set his army in motion; and the operations of the next few days may be summarised with sufficient accuracy as a cavalry raid northwards, but avoiding Cronje's left flank at Brown's Drift, to relieve Kimberley; combined with an infantry advance to cut him off. It was not possible to make the initial movements in the direction of the eventual advance, as the Magersfontein-Brown's Drift quadrant N.E. of Modder River was strongly held by the enemy, and disallowed a cavalry advance from below the junction of the Riet and the Modder in the direction of Kimberley except by a westerly detour which could not be accommodated to the general scheme. In order to strike the practicable drifts on the two rivers above their confluence, it was necessary for the advance to be made along the curve of a parabola which issued from Modder River Station in a S.E. direction, and in a sixty-mile circuit crossed the rivers and finally approached Kimberley, only twenty miles distant from the starting point, almost in the opposite direction. At midday on February 11 the Cavalry Division under French reached Ramdam, a farm east of Graspan and fronting the drifts of the Riet, where the Army was being concentrated for the advance. Some hours elapsed before Cronje became aware that French had trekked away to the S.E., and to his slow and sullen spirit the movement did not appear to have much significance. He was persuaded that the British never trusted themselves much more than a day's march away from a railway. It was only a demonstration, a reconnaissance. He did, however, take certain precautions which, if they had been devised with a true appreciation of the situation and intelligently carried out, might have seriously checked French. He assumed that the initial direction of French's march would be continued indefinitely towards Koffyfontein, possibly even that it was a retirement from the Modder River position caused by bad news from the centre, and he sent a commando of observation, under C. de Wet, up the right bank of the Riet. The most adroit and skilful movement of the war had now begun without Cronje's comprehending its object. But French did not complete his first day's work very auspiciously. His supply column was far behind when he reached Ramdam, and owing to a misunderstanding Hannay's Brigade of Mounted Infantry from Orange River, which was instructed to join him, did not turn up: conflicting orders had resulted as usual, _ordre_, _contr'ordre_, _désordre_. French, however, felt himself strong enough to continue his march without Hannay, who, on his delayed march to Ramdam, engaged a detached body of Boers and thereby strengthened the enemy's conviction that Koffyfontein was the objective.