Once more, therefore, Lieut. Girouard and his staff had to make the most strenuous efforts, and these were again so successful that the line was carried to the Atbara early in July. It was of the greatest service in facilitating the concentration of an Anglo-Egyptian Army, 22,000 strong, at Wad Hamed, and the victory of Omdurman, on September 2, 1898--when 20,000 of the enemy were killed or wounded--followed by the occupation of Khartoum, meant the overthrow of the Mahdi, the final reconquest of the Sudan, and the gaining of a further great triumph in the cause of civilisation. In the account of these events which he gives in volume three of the "History of the Corps of the Royal Engineers," Colonel Sir Charles M. Watson says concerning this ultimate outcome of a rebellion which had lasted, altogether, for a period of eighteen years:-- Lord Kitchener, of course, by the skill and determination with which he conducted the operations to a successful termination, deserves the principal credit for the happy conclusion of the campaign. But it must not be forgotten that a large part of the work was carried out by the officers of the Royal Engineers, especially those who had charge of the construction and maintenance of that railway without which, it is fair to say, the campaign could not have been conducted at all. The final triumph was the more gratifying because, although the desert railway had contributed so materially thereto, dependence upon it had not been without an element of serious risk which cannot be told better than in the words of Lord Cromer, in his book on "Modern Egypt":-- The interval which elapsed between the occupation of Abu Hamed and the final advance on Khartoum was a period of much anxiety. Sir Herbert Kitchener's force depended entirely on the desert railway for its supplies. I was rather haunted with the idea that some European adventurer, of the type familiar in India a century and more ago, might turn up at Khartoum and advise the Dervishes to make frequent raids across the Nile below Abu Hamed with a view to cutting the communication of the Anglo-Egyptian force with Wady Halfa. This was unquestionably the right military operation to have undertaken; neither, I think, would it have been very difficult of accomplishment. Fortunately the Dervishes ... failed to take advantage of the opportunity presented to them. To myself it was a great relief when the period of suspense was over. I do not think that the somewhat perilous position in which Sir Herbert Kitchener's army was undoubtedly placed for some time was at all realised by the public in general.