As regards form, they are weird enough for the wildest geological theories. All taper more or less toward the top. One is four-sided, like a pyramid; another, in shape a truncated cone, looks as if crowned with a pagoda summer-house; a third seems to be surmounted by a mosque and cupola; a fourth is scooped out in tiers of arches; a fifth is crowned, apparently, with a cairn of piled stones; and so on, with variations as endless as they are fantastic. A geologist might perhaps account for these caprices by showing how fire and earthquake and deluge had here succeeded each other; and how, after being first covered with volcanic stones and then split into chasms, the valleys thus opened had by and by been traversed by torrents which wore away the softer parts of the rock and left the harder standing. Some way beyond Kalat Adda, when the Abou Simbel range and palm island have all but vanished in the distance and the lonely peak called the Mountain of the Sun (Gebel esh-Shems), has been left far behind, we came upon a new wonder--namely: upon two groups of scattered tumuli, one on the eastern, one on the western bank. Not volcanic forms these; not even accidental forms, if one may venture to form an opinion from so far off. They are of various sizes; some little, some big; all perfectly round and smooth and covered with a rich, greenish-brown alluvial soil. How did they come there? Who made them? What did they contain? The Roman ruin close by--the two hundred and forty thousand[123] deserters who must have passed this way--the Egyptian and Ethiopian armies that certainly poured their thousands along these very banks, and might have fought many a battle on this open plain, suggest all kinds of possibilities and fill one’s head with visions of buried arms and jewels and cinerary urns. We are more than half-minded to stop the boat and land that very moment; but are content on second thoughts with promising ourselves that we will at least excavate one of the smaller hillocks on our way back. And now, the breeze freshening and the dahabeeyah tearing gallantly along, we leave the tumuli behind, and enter upon a more desolate region, where the mountains recede farther than ever and the course of the river is interrupted by perpetual sand-banks. On one of these sand-banks, just a few yards above the edge of the water, lay a log of drift-wood, apparently a battered old palm trunk, with some remnants of broken branches yet clinging to it; such an object, in short, as my American friends would very properly call a “snag.” Our pilot leaned forward on the tiller, put his finger to his lip and whispered: “Crocodilo!” The painter, the idle man, the writer, were all on deck, and not one believed him. They had seen too many of these snags already and were not going to let themselves again be excited about nothing. The pilot pointed to the cabin where L---- and the little lady were indulging in that minor vice called afternoon tea.