414 
TLTlfT'S NATUEAL HISTOEY. 
[Book 
The Nile begins to increase at tlie next new moon after 
the summer solstice, and rises slowly and gradually as the 
sun passes through the sign of Cancer ; it is at its greatest 
height while the sun is passing through Leo, and it falls as 
slowly and gradually as it arose while he is passing through 
the sign of Virgo. It has totally subsided between its 
banks, as we learn from Herodotus, on the hundredth day, 
when the sun has entered Libra. "While it is rising it has been 
pronounced criminal for kings or prefects even to sail upon 
its waters. The measure of its increase is ascertained by 
means of wells ^ Its most desirable height is sixteen -cubits^ ; 
if the waters do not attain that height, the overflow is not 
universal ; but if they exceed that measure, by their slowness 
in receding they tend to retard the process of cultivation. 
In the latter case the time for sowing is lost, in consequence 
of the moisture of the soil ; in the former, the ground is so 
parched that the seed-time comes to no purpose. The country 
has reason to make careful note of either extreme. When 
the water rises to only twelve cubits, it experiences the 
horrors of famine ; when it attains thirteen, hunger is still 
the result ; a rise of fourteen cubits is productive of glad- 
ness ; a rise of fifteen sets all anxieties at rest ; while an 
increase of sixteen is productive of unbounded transports of 
joy. The greatest increase known, up to the present time, 
is that of eighteen cubits, which took place in the time 
of the Emperor Claudius ; the smallest rise was that of five, 
in the year of the battle of Pharsalia^, the river by this 
prodigy testifying its horror, as it were, at the murder of 
Pompeius Magnus, When the waters have reached their 
greatest height, the people open the embankments and admit 
them to the lands. As each district is left by the waters, 
the business of sowing commences. This is the only river 
in existence that emits no vapours^. 
The Nile first enters the Egyptian territory at Syene^, on 
^ The principal well for this purpose was called the " Nilometer," or 
Gauge for the Nile." 
- On this suhject see Pliny, B. xviii. c. 47, and B. xxxvi. c. 11. 
3 Seneca says that the Nile did not rise as usual in the tenth and 
eleventh years of the reign of Cleopatra, and tliat the circumstance was 
said to bode ruin to her and Antony. — Nat. Qusest. B. iv. c. 2. 
He means dense clouds, productive of rain, not thin mists. See what 
is said of the Borysthenes by our author, B. xxxi. c. 30. 
^ Syene was a city of Upper Egypt, on the eastern bank of the Nile, 
