The 17th Bengal Regiment reached here last night in four barges towed by steamers, having made the distance in six days—without accidents—and is encamped on the west bank, opposite Halfa. The Beloochees, one of whose towing steamers ran aground near Derr, occasioning seven hours’ delay, will probably be here to-morrow. We are still in uncertainty as to the Arab plan of attack. The state of the river between Sarras and Semneh has prevented the use of the armed pinnace for reconnaissance purposes, and, although the Egyptian Camel Corps has repeatedly pushed forward along the west bank to within a few miles of Dal, their Commander has been able to gain very little insight into the enemy’s movements. It seems likely, however, that the Emir’s attack will be made on the east bank, but against what point between Sarras and Korosko it will be directed, there is as yet no sufficient indication. Sheikh Mustapha Gibran, who, with 150 men, occupies the Selima Oasis in the western desert some sixty miles inland from Dal, reports that, with the exception of a party of some fifty camp followers who came out to Selima in the beginning of last week apparently to obtain salt, he has been unmolested. On the east bank an attempt was made three days ago, at a reconnaissance into the Batn-el-Hagar, or ‘Belly of Rock,’ which borders the river between Sarras and the wells at Ambigol, forming an almost impassable barrier to troops. The enterprise was near resulting in the annihilation of the reconnoitring party; for the rocks were found to be full of Arabs, who sprang up on every side to the attack. Fortunately their dash was made too early, and Captain Beech was able to retire in good order, but with a loss of four men. We expect, however, that a very few days more will discover the tactics of the Emirs. WADY HALFA, _June 20th_, 6 A.M. A decisive engagement was fought yesterday near this place, with the result that after five hours of hard—in some cases of desperate—fighting, during the course of which the issue was at times uncertain, this latest tide of invasion has been rolled back once more into the desert. The Arabs have suffered terrible loss. Our own casualties, of which I have not as yet full particulars, are, I regret to say, very considerable. The Arab attack was intended to be a surprise, but this plan was partially defeated by one of those simple accidents which occasionally upset the calculations of commanding officers. Leaving aside Assouan and Korosko, the defending forces in and around Wady Halfa numbered, with details, medical staff, bearer companies, etc., about 6500 officers and men. This is without counting the navigating crews of the gunboats (armed with Krupp and machine guns), or the Indian regiment still on its way up the Nile.