[Footnote 187:  This same Nilometer is readily shown to the visitor at the south end of the Island of Roda, which is accessible by means of a ferry-boat from the Kasr-esh Shama, not far from the Kenisat Eliyahu, where the Geniza manuscripts were found.  See E.N.  Adler’s Jews in Many Lands, p. 28, also J.Q.R., IX, 669.  The Nilometer is in a square well 16 feet in diameter, having in the centre a graduated octagonal column with Cufic inscriptions, and is 17 cubits in height, the cubit being 21-1/3 inches.  The water of the Nile, when at its lowest, covers 7 cubits of the Nilometer, and when it reaches a height of 15-2/3 cubits the Sheikh of the Nile proclaims the Wefa, i.e., that the height of the water necessary for irrigating every part of the Nile valley has been attained.  The signal is then given for the cutting of the embankment.  We know that the column of the Nilometer has been frequently repaired, which fact explains the apparent discrepancy between the height of the gauge as given in Benjamin’s narrative and the figures just mentioned.]

[Footnote 188:  It has only been established quite recently that the periodical inundations of the Nile are not caused by the increased outflow from the lakes in Central Africa, inasmuch as this outflow is quite lost in the marshy land south of Fashoda.  Moreover, the river is absolutely blocked by the accumulation of the Papyrus weed, known as Sudd, the [Hebrew:  eis] of Scripture, Exod. ii. 3-5.  The inundations are brought about purely by the excessive rains in the highlands of Abyssinia, which cause the flooding of the Blue Nile and the Atbara in June and July and of the lower Nile in August and September.]

[Footnote 189:  In a Geniza fragment C quoted by Dr. Neubauer in J.Q.R., IX, p. 36, this city is called [Hebrew:].  Probably the first two letters denote that it is an island.  Compare the passage in Schechter’s Saadyana, pp. 90, 91, [Hebrew:].]

[Footnote 190:  Ashmun is described by Abulfeda as a large city.  We read in a Geniza fragment that David ben Daniel, a descendant of the Exilarch, passed through this place on the way to Fostat, J.Q.R., XV, 87.  The fourth channel is the Tanitic branch.  See p. 78, n. 2.]

[Footnote 191:  See Koran xii. 55.  Sambari, who being a native of Egypt knew Cairo well, explains very fully, p. 119, that Masr-el-Atika is not here referred to, but ancient Memphis, the seat of royalty in Joseph’s time.  He explains that it was situated on the left side of the Nile, two parasangs distant from Cairo.  See Reinaud’s Abulfeda, vol.  II, p. 140.]

     [Footnote 192:  See Makrizi, vol.  II, 464, and J.Q.R.,
     XV, p. 75; also XIX, 502.]