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remaining milliards of cubic metres of water when working in conjunc- 
tion with the Assuan Reservoir. The great weakness of this pro- 
jected lake has lain in the fact that by itself it could give a plentiful 
discharge in April and May, less in June, and very little in July, and 
it was for this reason that in my report of 1894 to the Egyptian 
Government I had reluctantly to recommend that it be not carried out. 
But when the Assouan reservoir is capable of supplying two milliards 
of cubic metres of water it will be possible to utilise the Moeris Lake 
to its utmost capacity. The Assouan Reservoir, being high above the 
level of the Nile can give its supply at the beginning or end of the 
summer; it can give it slowly or with a rush; while the projected 
Lake Moeris, being directly in communication with the Nile, and only 
slightly above low Nile level, its discharge would depend entirely on 
the difference of level between it and the Nile, and consequently as the 
summer advanced its level would gradually fall and the lake would 
not be able to give at the end of the summer a quarter of the discharge 
it could give at the beginning. 
But let us imagine that the reservoir and the lake are both com- 
pleted and full of water, and that it is the first of April. Lake Moeris 
will be opened on to the Nile and give all the water needed in that 
month, while the Assouan Reservoir will be maintained at its full level. 
In May, Lake Moeris will give nearly the whole supply and the reser- 
voir will give a little. In June the lake will give little and the 
reservoir much ; while in J uly the lake will give practically nothing 
and the reservoir the whole supply. Working together in this harmo- 
nious manner, the reservoir and the lake, which are the true complements 
of each other, will easily provide the whole of the water needed for Egypt. 
The Wady Rayan is a depression in the deserts to the south of the 
Fayoum and separated from the Fayoum by a limestone ridge. In 1888 
Col. Western recommended it very strongly as a reservoir. In this he 
was supported by Col. Ross, the first Inspector General of irrigation. 
On Col. Western’s leaving Egypt, the study was entrusted to me, and 
Messrs. Hewat and Clifton deputed to make a final project. The Wady 
Rayan project, with its plans and estimates, was published by the 
Egyptian Government in 1894. As I said before, I was reluctantly 
compelled to reject its adoption owing to the one radical defect already 
described. That defect will have been completely removed by the com- 
pletion of the Assouan Reservoir, when it will be possible to under- 
take the construction of the modern lake Moeris. 
