The cannon on the southern hills became more active and their shells caused the landscape surrounding the waterworks to be filled with geysers of dust. Troops which were stationed near the white smoke-stack suddenly spurred their horses forward and dashed northward to seek safety behind a long undulation in the ground. The artillerymen in the hills followed their movements with shells, and the dust-fountains sprang up at the very heels of the troops. The cannon at the drift joined in the attack on the horsemen scattered over the slope, and the big guns at the waterworks continued to reply vigorously. The men in the spruit were watching the artillery duel intently as they sped up and down the bottom of the water-less stream, searching for points of vantage. A large number of them moved rapidly down the spruit towards its confluence with the Modder River in order to check the advance of the troops driven forward by the shell-fire, and another party rushed eastward to secure positions in the rear of the British cannon at the waterworks. The banks of the stream still concealed them, but they dared not fire lest the enemy should disturb their plans. On and on they dashed, over rocks and chasms, until they were within a few hundred yards of a part of the British force. Slowly they crept up the sides of the spruit, cautiously peered out over the edge of the bank and then opened fire on the men at the cannon and the troops passing down the slope. Little jets of dust arose where their bullets struck the ground, men fell around the cannon, and cavalrymen quickly turned and charged toward the spruit. The shells of the cannon at the drift and on the southern hills fell thicker and thicker among the troops and the air above them was heavy with the light blue smoke of bursting shrapnel. The patter of the Boer rifles at the spruit increased in intensity and the jets of brown dust became more numerous. The cavalrymen leaped from their horses and ran ahead to find protection behind a line of rocks. The intermittent, irregular firing of the Boers was punctuated by the regular, steady reports of British volleys. The brown dust-geysers increased among the rocks where the British lay, and soon the soldiers turned and ran for their horses. Burghers crept from rock to rock in pursuit of them, and their bullets urged the fleeing horsemen on. The British cannon spoke less frequently, and shells and bullets fell so thickly around them that bravery in such a situation seemed suicidal, and the last artilleryman fled. Boers ran up and turned the loaded guns upon the backs of those who had operated them a few moments before.