204 THE DOWNFALL OF THE DERVISHES really be trusted to keep his boat in the deep channels with any certainty. Still, it must be remembered that the bed of the Nile is continually changing its position, and what are deep holes one year may be turned by next year’s flood into shallow pools. On the whole, It is astonishing that the river service was not frequently overtaken by disaster. The engines on a boat like the Zamaz were always on the verge of dissolution, the current was terrific, and all the vessels —gunboats, barges, and ghyassas— were loaded down to the water's edge. The barges, on which the troops were packed together with barely room to turn themselves, were especially liable to accident, as they were exceedingly top-heavy and loosely constructed. I remember seeing a gunboat gently collide with one of these barges as it lay, fortunately without any crew, off the bank at Wad Hamed. The whole structure collapsed at once; the top platform fell off, and in less than two minutes the remains of the barge and all its cargo that would float were drifting rapidly down the Nile.

One gunboat alone, the Zaphir, was overtaken by serious disaster. It happened as -| |