But on this particular day these chariots proved to be scarcely of any service, for the storm of rain, which, as already said, was of extraordinary violence, had made the ground slippery, and unfit for horses to ride over, while the chariots kept sticking in the muddy sloughs formed by the rain, and proved almost immovable from their great weight. Alexander, on the other hand, charged with the utmost vigour, because his troops were lightly armed and unencumbered. The Scythians and Dahae first of all attacked the Indians, and then the king launched Perdiccas with his horse upon their right wing. The fighting had now become hot everywhere, when the drivers of the chariots rode at full speed into the midst of the battle, thinking they could thus most effectively succour their friends. It would be hard to say which side suffered most from this charge, for the Macedonian foot-soldiers, who were exposed to the first shock of the onset, were trampled down, while the charioteers were hurled from their seats, when the chariots in rushing into action jolted over broken and slippery ground. Some again of the horses took fright and precipitated the carriages not only into the sloughs and pools of water, but even into the river itself. A few which were driven off the field by the darts of the enemy made their way to Porus, who was making most energetic preparations for the contest. As soon as he saw his chariots scattered amid his ranks, and wandering about without their drivers, he distributed his elephants to his friends who were nearest him. Behind them he had posted the infantry and the archers and the men who beat the drums, the instruments which the Indians use instead of trumpets to produce their war music. The rattle of these instruments does not in the least alarm the elephants, their ears, through long familiarity, being deadened to the sound. An image of Hercules was borne in front of the line of infantry, and this acted as the strongest of all incentives to make the soldiers fight well. To desert the bearers of this image was reckoned a disgraceful military offence, and they had even ordained death as a penalty for those who failed to bring it back from the battlefield, for the dread which the Indians had conceived for the god when he was their enemy had been toned down to a feeling of religious awe and veneration.