On the 19th there had been nothing more than long-range skirmishing in which the British losses were comparatively small. On the 20th it was determined to force the attack. Accordingly, on the night of the 19th, General Warren instructed General Clery, with General Hart's and General Woodgate's Brigades, and the six field batteries, to push the advance on the extreme left, against the enemy's positions on the long ridge which ran down from Spion Kop to the north-east. The ground over which the British troops were to advance is described as a succession of ridges, intersected at right angles by watercourses, cutting deep gorges in the mountain side, and thus sundering and separating the attacking force. Of shelter there was little or none; the advance had to be made from ridge to ridge, always under the fire of the vigilant enemy. [Illustration: MAP SHOWING THE MOVEMENTS OF SIR CHARLES WARREN'S ARMY UP TO THE NIGHT OF SPION KOP.] [Illustration: [_Photo by Bartlett, Shrewsbury._ MAJOR CHILDE.] [Illustration: _Alec Ball._] PRIVATE TOBIN CAPTURES BASTION HILL.] [Sidenote: JAN. 19-20, 1900.] _Capture of Three Tree Hill._] [Sidenote: Capture of Three Tree Hill and Bastion Hill.] [Sidenote: [JAN. 20, 1900.] During the night of the 19-20th a forward move was made. General Woodgate pushed out from the British camp and seized Three Tree Hill--a bastion jutting out from the north-western flank of Spion Kop. The Boers offered no resistance. The hill was the centre of a vast amphitheatre, crowned on all sides by Boer entrenchments; and though far below the crests which towered above it, it was the best artillery position that could be found, and here three of the British field batteries were planted. When day broke, the battle opened with the usual bombardment on the part of the field guns, the naval guns from Spearman's Hill and the howitzers from Potgieter's shelling the Boer position on Spion Kop from the other side. All day "the hills crashed with guns and rattled with musketry. At a little distance you might have supposed," writes Mr. Atkins, "that the resonant noises came from some haunted mountain, for the hills looked sleepy, and peaceful, and deserted, and there seemed to be no reason for all these strange sounds--the bark of field guns, the crackle of musketry, the rapping of Vickers-Maxims, and the tat-tat-tat-tat-tat-tat of Maxims." All day the thin straggling lines of British infantry pushed slowly forward--almost invisible upon the slopes of the hills--but in spite of splendid efforts the progress was painfully slow. The advance was made at first by small scattered parties of men, quickly following each other and using all the cover that could be found, hurrying from kopje to kopje. Then in heavier masses the main body of the infantry followed. General Hildyard's Brigade was on the left, General Hart's in the centre, and