On the 23rd, Lord Roberts and his majestical and magnificent apparatus of war, its thousands of gallant souls, its multiplicity of vehicles, its endless supplies and zoological train, encamped on the south bank of the Rhenoster River. The Boers, apparently demoralised in their preparations for resistance, and having had their left flank turned by Hamilton at Heilbron, were now continuously "on the run." Meanwhile burghers hourly came in to surrender arms and ammunition, the last vestige of truculence having evaporated. The Boer Government telegraphed to Lord Roberts offering to exchange an equal number of prisoners on parole, and threatening if the offer should be refused to remove from Pretoria to some other district the 4000 prisoners now confined there. As to the fate of the Johannesburg mines there was considerable uncertainty; reports declared they would be destroyed in the event of entry to the Transvaal by the British, and also that the town itself would be defended, as defence works were being rapidly pushed forward, guns got into position, and trenches and defences constructed. On the other hand it was stated that, on hearing of the threat to destroy the mines and possibly the town, Commandant Louis Botha had hastened to the President, and in a stormy interview had asserted his intention, if such a thing were contemplated, himself to defend Johannesburg from such an act of vandalism. He concluded by denouncing the diabolical intention and saying, "We are not barbarians." Mr. Kruger did not argue the subject--possibly his conscience tweaked him on the subject of barbarity--but gave in. Terrible altercations were daily taking place between the Boers, the Free Staters, and their mercenaries, and the burghers were inclined to throw all the blame of defeat on the Hollanders who had brought about the war and left the Boers to bear the brunt of the loss to life and property that hostilities entailed. These were merely reports, but they served, as the passage to the north proceeded, to show which way the wind blew. On the Queen's birthday the 4th Brigade of cavalry crossed the Vaal near Pary's Drift, and the 1st Brigade at a drift farther east of Pary's, while General Ian Hamilton's column was ordered to move towards Boschbank still higher up. They arrived just in time to save the coal-mines from being destroyed. The operation of crossing the Vaal was one of the most risky that has been undertaken in the campaign, as the road down to the drifts led through about six miles of mountainous country forming a narrow pass, well suited to Boer tactics. Fortunately, although the Boers were seen hovering in the vicinity, the arrival of the cavalry was unexpected, and they made no effective resistance.