[Sidenote: A New Enemy Appears.] It soon became evident that May, 1893, was not to be recorded in history as the month in which slave-trading Arabs had been finally repressed. A chief belonging to Ujiji, named Rumeliza, with a considerable force of Arabs, now appeared east of Tanganyika. Having penetrated as far as Kabambari, midway between Kassongo and the lake, he encamped there, and explained his presence by avowing his intention to reconquer Manyema. Rumeliza’s following was so numerous and so well equipped that October had arrived before Captain (for such he had recently become) Dhanis thought it expedient to move against him. When he did take the field, his force consisted of five officers (of whom Ponthier was one), about four hundred regulars, and three hundred auxiliaries; and they had with them the Krupp gun which had served them so well in many a battle. Unfortunately, ammunition for it was all but exhausted. On reaching the Arabs’ camp at Mwana Mkwanga, they were found to be very advantageously placed in two large, well-built bomas.[18] The first efforts to dislodge them met with no success. The Krupp gun proved of very little service. Of the scanty supply of ammunition, a large portion was wasted by the native troops through lack of skill in manipulating the gun, and finally they abandoned it, after which it was worked by European officers who could be ill spared for the duty. When one of his officers, De Lange, fell wounded, Captain Dhanis decided to retire, and a position was taken up scarcely inferior to that held by the Arabs. [Illustration: Post Office on River Bank, Boma.] [Illustration: Office of Secretary-General, Boma.]