At a very early stage of the siege General Gordon determined to try the metal of his troops, and the experiment succeeded to such a perfect extent that there was never any necessity to repeat it. On 16th March, when only irregular levies and detached bodies of tribesmen were in the vicinity of Khartoum, he sent out a force of nearly 1000 men, chiefly Bashi-Bazouks, but also some regulars, with a fieldpiece and supported by two steamers. The force started at eight in the morning, under the command of Colonel Stewart, and landed at Halfiyeh, some miles down the stream on the right bank of the Nile. Here the rebels had established a sort of fortified position, which it was desirable to destroy, if it could be done without too much loss. The troops were accordingly drawn up for the attack, and the gun and infantry fire commenced to cover the advance. At this moment about sixty rebel horsemen came out from behind the stockade and charged the Bashi-Bazouks, who fired one volley and fled. The horsemen then charged the infantry drawn up in square, which they broke, and the retreat to the river began at a run. Discouraging as this was for a force of all arms to retire before a few horsemen one-twentieth its number, the disaster was rendered worse and more disheartening by the conduct of the men, who absolutely refused to fight, marching along with shouldered arms without firing a shot, while the horsemen picked off all who straggled from the column. The gun, a considerable quantity of ammunition, and about sixty men represented the loss of Gordon's force; the rebels are not supposed to have lost a single man. "Nothing could be more dismal than seeing these horsemen, and some men even on camels, pursuing close to troops who with shouldered arms plodded their way back." Thus wrote Gordon of the men to whom he had to trust for a successful defence of Khartoum. His most recent experience confirmed his old opinion, that the Egyptian and Arab troops were useless even when fighting to save their own lives, and he could only rely on the very small body left of black Soudanese, who fought as gallantly for him as any troops could, and whose loyalty and devotion to him surpassed all praise. Treachery, it was assumed, had something to do with the easy overthrow of this force, and two Pashas were shot for misconduct on return to Khartoum.