Explosion followed explosion in quick succession until all four batteries were busily engaged. The cannonade grew loud and continuous. The rocket detachment began to fire, and the strange projectiles hissed and screamed as they left the troughs and jerked erratically towards the zeriba. In the air above the enclosure shell after shell flashed into existence, smote the ground with its leaden shower, and dispersed--a mere film--into the haze and smoke which still hung over the Dervish encampment. At the very first shot all the dirty-white figures disappeared, bobbing down into their pits and shelters; but a few solitary horsemen remained motionless for a while in the middle of the enclosure, watching the effect of the fire, as if it had no concern with them. The British infantry stood up on tip-toe to look at the wonderful spectacle of actual war, and at first every shell was eagerly scrutinised and its probable effect discussed. But the busy gunners multiplied the projectiles until so many were alive in the air at once that all criticism was prevented. Gradually even the strange sight became monotonous. The officers shut up their glasses. The men began to sit down again. Many of them actually went to sleep. The rest were soon tired of the amazing scene, the like of which they had never looked on before, and awaited impatiently further developments and 'some new thing.' After the bombardment had lasted about ten minutes a great cloud of dust sprang up in the zeriba, and hundreds of horsemen were seen scrambling into their saddles and galloping through a gap in the rear face out into the open sand to the right. To meet the possibility of an attempt to turn the left flank of the attack, the eight squadrons of cavalry and two Maxim guns jingled and clattered off in the direction of the danger. The dust, which the swift passage of so many horsemen raised, shut the scene from the eyes of the infantry, but continual dust-clouds above the scrub to the left and the noise of the Maxims seemed to indicate a cavalry fight. The Baggara horse, however, declined an unequal combat, and made no serious attempt to interfere with the attack. Twice they showed some sort of front, and the squadrons thought they might find opportunity to charge; but a few rounds from the Maxims effectually checked the enemy, inflicting on each occasion the loss of about twenty killed and wounded. With the exception of one squadron detached on the right, the Egyptian cavalry force, however, remained on the left flank, and shielded the operations of the assaulting infantry.