The enemy's general idea was a defensive occupation of the Colenso position, although Botha, with characteristic spirit, proposed to send a commando across the river to face the British on the open. The initiative, always a disadvantage when attacking an enemy strongly posted and entrenched, was thus imposed upon Buller. It was not doubted that he would be compelled to make a frontal attack on Colenso and in this the Boers showed the more correct appreciation of the situation. Botha hoped to lure Buller on and was prepared even to allow him to cross the river; and having crushed him to act upon the British flanks, an operation which the wide extension of Botha's front from Hlangwhane to Robinson's farm, a distance of seven miles, gave him a good chance of being able to carry out. If necessary, reinforcements could be drawn from the investing circle around Ladysmith, which seemed to be detaining more burghers than were necessary for the maintenance of the siege. Buller proclaimed his intention of attacking Botha by a preliminary bombardment of the Colenso kopjes on December 13 and 14; but the burghers lay low and gave so little indication of their presence that it almost seemed that they had abandoned the line of the Tugela. The British Army was encamped near Chieveley four miles south of Colenso. On the evening of December 14 the scheme of attack was delivered to the Brigadiers. The leading idea of it was a frontal attack to be delivered from the village of Colenso, where the Tugela is crossed by an iron railway bridge as well as by an iron wagon bridge. The latter had been left intact by the enemy, possibly in order to entice the British troops across the river. Buller appears to have been unaware how far the Boer trenches extended towards the west, and to have assumed that only the kopjes immediately opposite Colenso were occupied. Hildyard's Brigade was ordered to march in the direction of the "iron bridge,"[21] to cross at that point, and then to "seize the kopjes north of the iron bridge." The attack on the enemy's right, which was believed to be weak, was assigned to Hart's Irish Brigade. He was instructed to cross the Tugela at a bridle drift about two miles west of Colenso and work down the left bank towards the occupied kopjes. Two infantry Brigades were retained as reserves to be used when required; and the mounted Brigade was ordered to move towards Hlangwhane and occupy it, if possible, and cover the right flank; but the weakness of the Boer position on that hill, which was cut off by the river from the main line of defence, does not seem to have been realized. A few batteries were sent with Hart, but the bulk of the artillery was ordered east of the railway to support Hildyard.