days most of them presuppose the availability of reinforced concrete and
heavy earth-moving Al.
equipment. I understand that we will not have the benefit of these
modern aids.'
'Remember Taita,' Nicholas exhorted him. 'He did it without bulldozers.'
'On the other hand, the Egyptians probably had unlimited numbers of
slaves at their disposal.'
'Slaves I can promise you. Or the modern equivalent thereof. Unlimited
numbers? Well, perhaps not.'
'The more tabour you can provide, the sooner I can divert the flow of
the river for you. We are agreed that this has to be done before the
onset of the rainy season.'
'We have two months at the most.' Nicholas dropped his flippant
attitude. 'As regards the provision of tabour, I will be relying on
enlisting the aid of the monastic community at St. Frumentius. I am
still working out a sound theological reason that might convince them to
take part in the building of the dam. I don't think they will fall for
the idea that we have discovered the site of the Holy Sepulchre in
Ethiopia and not in Jerusalem.'
'You find me the tabour, and I will build your dam,' Sapper grunted. 'As
you said earlier, the old ways are the best. It is almost certain that
the ancients would have used a system of gabions and coffer dams to lay
the foundations of the original dam.'
'Sorry,' Royan interrupted. 'Gabions? I don't have an engineering
degree.'
'I am the one who must apologize.' Sapper made a clumsy attempt at
chivalry. 'Let me show you my drawings.' He turned to the board. 'What
this fellow Taita probably did was to weave huge bamboo baskets, which
he placed in the river and filled with rock and stone. These are what we
call gabions.' He indicated the plans on the board. 'After that he would
have used rough-cut timber to build circular walls between the gabions -
the coffer dams. These he would also have filled with stone and earth.'
'I get the general idea,' Royan said, sounding dubious, 'but then it is
not really necessary for me to understand all the details.'
'Right you are!' Sapper agreed heartily. 'Although the major assures me
that there is all the timber we will need on the site, I plan to use
wire mesh for the construction of the abions and human tabour for the
filling of the mesh 9 nets with stone and aggregate.'
'Wire mesh?' Royan demanded. 'Where do you hope to find that in the
Abbay valley?'
Sapper began to reply, but Nicholas forestalled him.'
will come to that in a moment. Let Sapper finish his lecture. Don't
spoil his fun. Tell Royan about the stone from the quarry. She will
enjoy that.'
'Although I have designed the dam as a temporary Structure, we have to
make certain that it is capable of holding back the river long enough to
enable the members of our team to enter the underwater tunnel in the
downstream pool Safely-'
'We call it Taita's pool,'Nicholas told him, and Sapper nodded.
