Only a few days before, a similar misadventure had attended the construction of the Heilbron-Vrede blockhouse line. Rimington and Damant had hardly returned to Heilbron after Elliott's third drive when they were ordered out beyond Frankfort, to the assistance of the blockhouse builders, who were being worried by a commando under Wessels, which De Wet had sent out after the Council of War. Near the Wilge River they acted on a front too extended; and a portion of Damant's force was deceived by the slim tricks of a party of Boers working in cavalry formations and many of them dressed in khaki uniforms. In order to keep up the illusion they fired at detached parties of their own side, and in the end Damant was overwhelmed on a hill, with a loss of nearly 90 per cent. of casualties, before the rest of his command came up and drove away the assailants. Rimington was too far away either to prevent or to retrieve the disaster. When the "drives" were renewed in the northeastern districts of the Orange River Colony at the end of January, 1902, the experience of the last few months had shown that they must be conducted on new methods. Hitherto the typical "drive" had been a net or nets cast too often hastily and at random, the meshes of which were large, irregular, and easily cut. The new "drive" was a bar of steel pushed steadily forward by simultaneous action throughout its length, and with its ends resting on the two completed blockhouse lines running eastward from Heilbron and Kroonstad. [Sidenote: Map, p. 260.] The Drive, Mark II, was inaugurated on February 3. De Wet, who on January 10 had had a hurried interview with Steyn near Reitz, was lying at Elandskop between Heilbron and Reitz, and again concentrating his scattered burghers and planning an escape with them to the south across the Kroonstad-Bethlehem blockhouse line. Mears, on his way to rejoin De Wet, ran into a column under Byng, to whom he lost the guns captured by De Wet at Groen Kop. On February 5 a force of 9,000 men under Elliott, Rawlinson, Byng, and Rimington formed up on a line stretching from Frankfort to Kaffir Kop. The composition of this force showed the altered conditions of warfare. It included very few field guns, but no less than 2,200 horse and field gunners acting as Mounted Riflemen. Next day the first impulse was given to the Bar, the blockhouse lines north and south, as well as the railway, having been strengthened. The whereabouts of De Wet were approximately known.