The war now entered fully into its “blockhouse and drive” phase.  The use of these expedients in combination was, it is believed, new to military history.  The principle of the blockhouse had already been tentatively adopted in South Africa without much success, notably between Bloemfontein and Thabanchu, where a line of posts was established which on three occasions was cut by De Wet.[55] The chief defect of the blockhouse is its vulnerability to shell fire; but by this time the Boer artillery was a negligible quantity.  Its adoption on a large scale dates from the time of Lord Kitchener’s taking over the command.  The expedient was, in the first instance, applied to the railways as a protection against the raids to which they were subject; and after July, 1901, it was extended to the open veld.  Subsidiary lines of blockhouses, which in general jutted out at right angles to the railways and in most cases ran along the cross-veld roads changing direction as circumstances required, were built.  They acted as fences to obstruct or to deflect the movements of the enemy and enclosed areas greatly differing in size.

The longest blockhouse line, which was, however, not completed until a few weeks before the end of the war, extended from Victoria Road Station to Lambert’s Bay on the Atlantic, a distance of 300 miles.  In the vicinity of Johannesburg, and in the Central districts of the Orange River Colony west of the railway, cordons of posts manned by the South African Constabulary took the place of blockhouse lines.  These posts, which were established at wider intervals apart than the blockhouses, were intended to act as bases for minor clearing operations.  They offered little or no obstruction to a Boer commando on trek.  The blockhouse lines were resolutely extended by Lord Kitchener in every direction; and by the end of the war there was scarcely a district in the spacious area of hostilities that was not impaled upon them or helplessly clutched in their fatal grasp.

The “Drive” as a military weapon is as old as the time of Darius.  The first use of it in South Africa, on a large scale, was French’s movement through the Eastern Transvaal in February, 1901.[56] The “Drive” has been criticized as an awkward attempt to perform, with one and the same force, two distinct operations of war; namely, the coercion of the non-military population and the defeat of the enemy’s troops.  The dual task deprives the force set to it of mobility and power of initiative.

As a detail of abstract and orthodox military criticism the objection is sound; but it ignores the special local circumstances of the case.  In the vast area on which the British Army was operating it was not possible to separate the two objectives.  Moreover, the purely military resources of the enemy were waning; and the contest was resolving itself into an effort to put pressure on the country at large, rather than to smash the dwindling, evasive, and centrifugal