Great success having attended the construction of the line of defensible posts extending across the Orange River Colony, from Jacobsdal to Ladybrand, a gradual development of the blockhouse system was kept up in order to maintain the security of traffic and form a barrier to the encroachment of roving bands. A continuous line of blockhouses at intervals of a mile apart, following the course of the river from Aliwal North to Bethulie, and running from thence along the railway _viâ_ Stormberg, Rosmead, Naauwpoort Junction, de Aar, to Kimberley was commenced in July, and another (starting northward from Frederikstad to the source of the Mooi River, Breedt's Nek along the Magaliesberg) for the purpose of maintaining the connection with the garrison at Commando Nek was begun at the same time by two battalions under the command of Colonel Mackenzie, Suffolk Regiment. Colonel Pilkington, with the South African Constabulary, engaged in like activities to the east of the Pretoria-Vereeniging line, his line of posts extending from Eerste Fabriken, by Springs and Heidelberg, to the Vaal River. It was thus hoped that between the Vaal and Modder Rivers, by means of a converging number of columns, the Boers would be swept from all sides against the British barriers and driven to surrender. To this end the two forces of Generals Bruce-Hamilton and C. Knox were operating in the Orange River Colony during the last half of July. The former had thus disposed his troops. At Jacobsdal and Luckhoff were Colonels Williams and Dawkins respectively, and moving on Edenburg _viâ_ Wepener, were Colonels Rochfort and Du Moulin. Edenburg was reached on the 17th of July, after which all the columns were moved west of the railway, to act as a support to the barrier of police posts along the Modder from Bloemfontein to Jacobsdal, garrisoned by South African Constabulary, and also as stops to the enemy when pressed southward from the Vaal River. To Colonel Rochfort was allotted the region around Petrusburg; farther west (at Blaauwbank and Negdraai Drifts on the Riet River) came Colonel Williams, while the line of the Orange River (between Norval's Pont and Ramah) was guarded by the columns of Colonels Du Moulin and Dawkins. Colonel Rochfort very speedily reaped the reward of many days and nights of vigilance. Rumour told of a burgher gang under Commandant Myburg which, with a view to rushing into the Cape Colony, was encamped on the Riet, and to defeat this programme he made an arrangement as smart as it was successful. On the night of the 27th of July, acting in concert with Colonel Lowry Cole (who was under his orders in the vicinity), he marched in the small hours to the spot--between Dassiespoort and Jagersfontein Drift--where the laager had been located. Dawn found the enemy surrounded. There was the usual rush, and roar, and scrimmage, in the course of which Myburg was dangerously wounded. The commandant was secured, together with his Field-Cornet,