Their concentration had not escaped the notice of the British military authorities, who welcomed any movement which might bring to a focus that resistance which had been so nebulous and elusive.  Lord Kitchener having once seen the enemy fairly gathered into this huge cover, undertook the difficult task of driving it from end to end.  For this enterprise General French was given the chief command, and had under his orders no fewer than seven columns, which started from different points of the Delagoa and of the Natal railway lines, keeping in touch with each other and all trending south and east.  A glance at the map would show, however, that it was a very large field for seven guns, and that it would need all their alertness to prevent the driven game from breaking back.  Three columns started from the Delagoa line, namely, Smith-Dorrien’s from Wonderfontein (the most easterly), Campbell’s from Middelburg, and Alderson’s from Eerstefabrieken, close to Pretoria.  Four columns came from the western railway line:  General Knox’s from Kaalfontein, Major Allenby’s from Zuurfontein (both stations between Pretoria and Johannesburg), General Dartnell’s from Springs, close to Johannesburg, and finally General Colville (not to be confused with Colvile) from Greylingstad in the south.  The whole movement resembled a huge drag net, of which Wonderfontein and Greylingstad formed the ends, exactly one hundred miles apart.  On January 27th the net began to be drawn.  Some thousands of Boers with a considerable number of guns were known to be within the enclosure, and it was hoped that even if their own extreme mobility enabled them to escape it would be impossible for them to save their transport and their cannon.

Each of the British columns was about 2000 strong, making a total of 14,000 men with about fifty guns engaged in the operations.  A front of not less than ten miles was to be maintained by each force.  The first decided move was on the part of the extreme left wing, Smith-Dorrien’s column, which moved south on Carolina, and thence on Bothwell near Lake Chrissie.  The arduous duty of passing supplies down from the line fell mainly upon him, and his force was in consequence larger than the others, consisting of 8500 men with thirteen guns.  On the arrival of Smith-Dorrien at Carolina the other columns started, their centre of advance being Ermelo.  Over seventy miles of veld the gleam of the helio by day and the flash of the signal lamps at night marked the steady flow of the British tide.  Here and there the columns came in touch with the enemy and swept him before them.  French had a skirmish at Wilge River at the end of January, and Campbell another south of Middelburg, in which he had twenty casualties.  On February 4th Smith-Dorrien was at Lake Chrissie; French had passed through Bethel and the enemy was retiring on Amsterdam.  The hundred-mile ends of the drag net were already contracted to a third of that distance, and the game was still known to be within it.  On the 5th Ermelo was occupied, and the fresh deep ruts upon the veld told the British horsemen of the huge Boer convoy that was ahead of them.  For days enormous herds, endless flocks, and lines of wagons which stretched from horizon to horizon had been trekking eastward.  Cavalry and mounted infantry were all hot upon the scent.