Graham's men, who had been suffering very much from their long exposure to the sun without food, were then ordered back to their camps. The matter, however, was not destined to end here, for at 4.30 the enemy advanced his infantry in great force, displaying a line of skirmishers at least a mile in length, with which he sought to overlap the left of Graham's front. This movement was supported by a heavy and well-directed artillery fire, which searched the camp and wounded a sick officer in the building occupied as a hospital. The dispositions to meet the attack were as follows:--On the left the Marine Artillery were directed to take up a position on the south bank of the Canal, whence they could check the enemy's advance by a flank fire. In the centre was the Duke of Cornwall's Regiment, extended in fighting line, about 800 yards to the right rear of the Marine Artillery, and the York and Lancaster extended the fighting line of the Duke of Cornwall's with two and a half companies, keeping the remainder in support and reserve. The position of the infantry was an irregular echelon, the right thrown back. A troop of the 7th Dragoon Guards was kept on this flank, and the two 13-pounders, now reinforced by two others, took up a position on the ridge, and promptly replied to the Egyptian cannonade. Unfortunately, these guns had only the ammunition contained in their limbers and had soon to cease firing for want of a further supply, though they did good service while it lasted. The reason of the ammunition failing was the heaviness of the road from the base to the front. Efforts were made to get up a proper supply, but the waggons stuck in the sand and so arrived late. The Mounted Infantry and a dismounted detachment of the 4th Dragoon Guards occupied a portion of the gap between the Marine Artillery and the Duke of Cornwall's Regiment, and although the attacking force made persistent efforts to break through at this point, it failed owing to the steady fire of the Marine Artillery and the little band of Dragoons and Mounted Infantry. The enemy made repeated attempts to overcome this resistance, putting a number of men across the Canal; and three times their guns were kept from advancing by the horses and men being shot when trying to press past. Feeling secure on his left, Graham turned his attention to the right flank of his position. On the first notice of the attack (4.30 p.m.) he had sent a message to General Drury-Lowe by heliograph, and by a mounted officer to Mahsameh, three or four miles distant, requesting him to move up the Cavalry Brigade to cover the right flank, and also to send forward the Marine Light Infantry as a reinforcement. At 5 p.m. Graham sent a further order for the cavalry to advance under cover of the ridge on the right, fall upon the left flank of the enemy's skirmishers and roll up his line. The particulars of the cavalry attack made in pursuance of this order are given later on.