Zero line of the 
Nilometer of Rhoda. 
MR. HORNER ON THE ALLUVIAL LAND OF EGYPT. 
115 
From the increased fertility of the land by the overflowing of their river, the 
earliest inhabitants of Egypt must have been led to watch the rise and fall of the 
water with anxious care. At an early period in the history of the country they con- 
trived an instrument to measure its diurnal changes, a Nilometer, which was erected 
on the island of Elephantine near Assouan. That instrument is now only an object 
of interest to the antiquarian, as a ruin is all that is left of it ; but it was in a state 
of considerable preservation a little more than fifty years ago when visited by the 
French engineers*. I describe it now, as it then existed, because special reference 
will be made hereafter to this ancient standard of the Nile’s annual increase. It is 
near the south end of the island, and is described by Strabo from personal observa- 
tion, he having twice visited the spot. 
The French engineers have given the following description of it as they found it. 
It was in a building constructed of regular horizontal layers of sandstone, having two 
flights of steps, at right angles to each other. One of the walls of the staircase was 
marked with a vertical groove, crossed by horizontal lines, at regular distances, 
each of these divisions being a cubit. Three of these divisions were marked with the 
(ireek numerical letters, the highest being KA, or 24 ; the second KF, or 23 ; 
the fifth K, or 20. The engineers assumed that at the time this Nilometer was 
constructed, the number 24 marked the greatest rise of the Nile then known-^. 
M. Girard and his companions made an exact measurement of the cubits from 24 to 
18, and the result gave 527 millimetres for each cubit, =20*75 English inches. Sir 
Gardner Wilkinson, from personal observation and examination of the different 
* Among the scientific men who accompanied the French army in 1799, we find the following celebrated 
names : — Berthollet, Monge, Fourier, Malus, Girard, and M. Cordier the geologist, still living. 
M. Girard occupied the rank of Ingenieur en Chef des Fonts et Chaussees. Dolomieu also went, hut did 
not remain. 
t Girard, Observations sur la Vall6e d’Egypte, et sur I’exhaussement seculaire du Sol qui la recouvre : 
Memoires de I’Acad. Roy. de I’Institut, 1817, tom. ii. p. 261, and Description de I’Egypte Antique, sur k 
Nilometre de I’lle Elephantine. 
R 2 
