facing the board. He stood at the board and picked up a silver-topped
swagger stick from the table, brandishing it like a schoolmaster's
pointer.
'Class will come to order.' He rapped on the board.
'The first thing you have to do is convince me that we will be able to
pick up the spoor of Taita again after it has had several thousand years
to cool. Let us first consider the geographical features of the Abbay
gorge.'
Nicholas described the course of the river on the satellite photograph
with his pointer. 'Along this section the river has cut its way through
the flood basalt plateaux.
In places the cliff of the sub-gorge are sheer, as high as four or five
hundred feet on each side. Where there are intrusive strata of harder
igneous schists the river has not been able to erode them. They form a
series of gigantic steps in the course of the river. I think you are
correct in your assumption that Taita's 'steps' are actually waterp
falls.'
He came to the table and picked out a photograph from amongst the
bundles of papers that covered it. 'I took this in the gorge during the
Armed Forces Expedition in 1976. It will give you an idea of what some
of those falls are like.'
He passed her a black and white riverscape of towering cliffs on either
hand and a cascade of water that seemed to fall from the heavens to
dwarf the tiny figures of half-naked men and boats in the foreground.
'I had no idea it was. like thad' She stared at it in awe.
'Doesn't do justice to the splendid desolation down he told her. 'From a
photographer's there in the gorge, gra point of view there. is no place
to stand from which you can get it all into perspective. But at least
you can see how that waterfall would halt a party of Egyptians coming
upriver on foot, or at least with pack horses. There is usually some
sort of path alongside the cataracts made by elephant and other wild
game over the ages. However, there is simply no way to bypass waterfalls
such as this one, and to get around those cliffs.'
She nodded, and he went on, 'Even coming downstream we had to lower the
boats and all our equipment down each set of waterfalls on ropes. It
wasn't easy.'
'Let us agree that it was a waterfall that stopped them going further -
the second waterfall from the westerly approaches,' she conceded.
Nicholas picked up the swagger stick and on the satellite photograph
traced the course of the river up from the dark wedge shape of the
Roseires dam in central Sudan.
'The escarpment, rises on the Ethiopian side of the border, that is
where the gorge proper begins. No roads or towns in there, and only two
bridges far upstream. Nothing for five hundred miles except racing Nile
waters and savage black basalt rock.' He paused to let that sink in.
'It is one of the last true wildernesses on earth, with an evil
reputation as the haunt of wild animals and even wilder men. I have
marked the main falls that show in the gut of the gorge here on the
satellite photo.' With the pointer he picked them out, each circled
neatly in red marker pen.
