NILOM'ETER (the measurer of the Nile), the name of two buildings existing in Egypt, one in the island of Rhoda, opposite to Cairo, the other at Elephantine, close to Assonan, in 24° 5' 23' ii. lat. The first consists of a square well, in which is placed a graduated pillar of marble, and is called a mekkias or measure; the pillar contains 24 devalchs or cubits, each of which measures 21.386 in., or according to Greaves, 1824 ft., and contains 24 digits; but in its present state it does not appear to have been intended to mark a rise of more than 16 cubits. This pillar is exceedingly slender. The building . formerly had a dome, bearing a Cufic inscription, dated 847 A.D., and is said to have been erected by the calif Mamma, or his 'successor, Wathek Billuh. The first-mentioned monarch is said to have erected another nilometer at the village of Banbenonda, in the Saeed, and to have repaired an old one at Eklimin. The calif El Motawukkel built the present one. The mode of calculating the increase at the nilometer is rather com plex, and to a certain extent, arb,itrary, pplitical and financial reasons rendering the process a mystery even to the halide's. At the present day the Nile is supposed to have -risen to 18 cubits when the canals are cut; this is the height of the lowest inundation; 19 cubits are considered tolerable, 20 excellent, 21 adequate, and 22 complete; 24 are ruinous. In the time of Edrisi, however, 16 cubits were considered sufficient. The object of these nilometers was to measure the amount of taxation to be imposed on the country. The nilometer at Cairo is, however, much more recent than that existing at
i Elephantine, which consists of a staircase between two walls descending to the mile. One of these walls has engraved on it a series of lines at proper intervals marking the • different elevations to which the river rose under the Ctesars. The cubits here are divided into 14ths or double digits, and measure 1 foot 8.625 inches. This nilometer is described by Strabo. The probability is that many nilometers existed iu the days of the Pharaohs, probably one in each city. In the days of 3licris 8 cubits were sufficient, but 15 or 16 were required in the time of Herodotus, 456 m.o., and this was the mean under the Romans. According to Pliny, if the inundation did not exceed 12 cubits it produced a famine, 13 starved the country, 14 rejoiced it, 15 was safety, and 16 delight, and this number is symbolically represented by the number of children playing round the river god on statues of the Roman period. The oldest nilometer appears to have been erected at Memphis, and it was transferred by Constantine to a church in the vicinity of the Serapeiutn; but Julian sent it back to this temple, where it remained till its destruction by Theodosius. At the present day the rise is watched for with anxiety, and proclaimed by four criers.—Herodotus, ii. 13; Strabo, lib. xvii.; Wilkinson, Topogr. of Thebes, pp. 311-17. Hekekyan Bey, Siriadic Monuments (Load. 1863), p. 145.