Captain Fisher of the Royal Navy took possession of a railway train and made of it a moving battery. Its armament consisted of two heavy guns and some gatlings; the trucks were protected by sand-bags, and the battery was manned by sailors. This train did great service, as the line of railway ran from Alexandria through the rebel camp, and when reconnaissances were made the movable battery accompanied the troops, and by its fire greatly facilitated the operation. Until the end of July the principal part of the work of defending Alexandria and checking the army of Arabi fell upon the Naval Brigade, but by that time so large a number of troops had arrived that the services of the sailors on shore were no longer required, and, with the exception of those serving in Captain Fisher's battery, they returned to their respective ships. The marines, however, remained on shore and took part in a sharp engagement which took place on the 5th of August. Sir Archibald Alison was desirous of discovering the exact position and force of Arabi's advance line of defences, and a reconnaissance, composed of six companies of the 60th Rifles, four companies of the 38th, and four of the 46th, were told off for the service; and seven companies of marines under Colonel Tewson were ordered to advance along the railway embankment in company with the ironclad train. The Rifles were to march by the canal, and the two parties would join at the point where the canal and railway approach closely to each other. The ground between the line taken by the two columns consisted of fields and marshy swamps. No sooner had the advance begun than a movement was visible in the enemy's lines, and the Egyptians were soon seen extending in skirmishing order 1000 yards in front of the 60th. They took up their position in a deep ditch which crossed the British line of advance, and behind which was a thick jungle, and opened a heavy fire upon the Rifles. The troops advanced steadily in skirmishing order, opening fire upon their almost invisible foes, whose heads only could be seen when they raised them to discharge their muskets. The Egyptians fired high, and although a hail of bullets swept over the heads of the advancing troops there were but few casualties. When the Rifles approached the ditch, the supports were brought up and a rush was made, when the Egyptians at once forsook their position and fled through the jungle.