— 70 — 
They contain only about 6 per cent, of pure nitrates, but as they are 
on the edge of the Nile, in a perfectly cloudless and very dry country, 
it might be possible, with the aid of the plentiful supply of water 
always at hand to profitably extract pure nitrates. The demand for 
nitrates is without limit in the Nile Yalley, as Nile water, though rich 
in everything else, is exceedingly poor in nitrates. 
The perennial canals and collateral works have cost £4.50 per acre, 
and the maintenance charges are £'10 per acre. The perennially irri- 
gated lands are let at £5 to £8 per acre per annum as against £3 to £5 
for the basins lands. 
30. Flood protection in Egypt. — The Nile during high floods 
is considerably above the level of the country, which is protected by 
embankments stretching from Assouan to the sea. In Upper Egypt, 
a very high flood is one metre above the country ; in Middle Egypt 
it is 2 metres, and the same on the Rosetta branch of the Nile. On 
the Damietta branch it is 3 • 50 metres in places. 
In parts of Upper Egypt, but nearly everywhere in Lower Egypt, 
the Nile on curves is protected by stone spurs. These spurs contain 
each from 4,000 to 250 cubic metres. They are very effective where 
the Nile bank has been well thrown back below them to a distance of 
some 50 metres on a length of at least 100 metres. This allows the 
waters of the flood to swirl harmlessly in whirlpools below the spurs 
while the banks are far removed from their action. 
When we first came to Egypt, we found that the policy was to spread 
the flood into as many channels as possible and protect the whole of 
them with tens of thousands of corvee, in addition to the corvee on the 
Nile banks. We changed that and concentrated our energies on the 
Rosetta and Damietta branches. 
In 1861, 1863, 1866, 1869, 1874, and 1878 the Damietta branch 
was badly breached. There has been only one serious breach on the 
Rosetta branch, and that was in 1863. The great breach of 1878 on 
the Damietta branch was attended with serious loss of life ; but far 
more serious was the breach of 1863 on the Rosetta branch not far 
from its head. The whole western half of the Delta proper was 
swept by the river, and as the canals there have not got good high 
banks, the people had no place of shelter to flee to and were drowned 
in very great numbers. The same thing would happen again if a 
breach were to occur now, only the damage would be far more 
serious. The country is covered with villas and rich plantations and 
