Nilometer

Measuring shaft of the nilometer on Roda Island, Cairo

A nilometer was a structure for measuring the Nile River's clarity and water level during the annual flood season.[1] There were three main types of nilometers, calibrated in Egyptian cubits: (1) a vertical column, (2) a corridor stairway of steps leading down to the Nile, or (3) a deep well with culvert.[1] If the water level was low, the fertility of the floodplain would suffer. If it was too high, the flooding would be destructive. There was a specific mark that indicated how high the flood should be if the fields were to get good soil.[1][2]

Nilometers originated in pharaonic times, were also built in Roman times, and were used until the Aswan Dam rendered them obsolete in the 1960s.

Description

Nilometer shown c.1800 at the southern tip of Roda Island

Between July and November, the reaches of the Nile running through Egypt would burst their banks and cover the adjacent floodplain. When the waters receded, around September or October, they left behind a rich alluvial deposit of exceptionally fertile black silt over the croplands. The akhet, or Season of the Inundation, was one of the three seasons into which the ancient Egyptians divided their year.

Importance

The annual flood was of great importance to Egyptian civilization. A moderate inundation was a vital part of the agricultural cycle; however, a lighter inundation than normal would cause famine, and too much flood water would be equally disastrous, washing away much of the infrastructure built on the flood plain. Records from AD 622–999 indicate that, on average, 28% of the years saw an inundation that fell short of expectations.[2]

Palermo Stone, 5th Dynasty (2392 B.C.E-2283 B.C.E)

Across Egypt various nilometers recorded readings of the Nile's annual levels could be found. An uncovered fragment of a recovered Egyptian stele "Royal Annals of the Old Kingdom" depicts a fragment of the stele known as the “Palermo stone” deemed to be from the times of the First Dynasty around 3,000 B.C.E.[3] The Palermo Stone reported systems of measurements utilizing units such as cubits, palms, and fingers.[4]

The ability to predict the volume of the coming inundation was part of the mystique of the Ancient Egyptian priesthood. The same skill also played a political and administrative role, since the quality of the year's flood was used to determine the levels of tax to be paid. This is where the nilometer came into play, with priests monitoring the day-to-day level of the river and announcing the awaited arrival of the summer flood.

Religious attributes related to the Nile and its interwind existence of the Egyptian's ideology or belief in Ma'at (a system of natural balance), Nilometers were accessible to only members of their cities respects priesthoods and nobles like that of Pharoses.[5] The exclusion on who may access these structures ensured both accountability in proper readings, as well as maintaining political control to both the religious communities and ruling classes.[5]

Designs

Conical structure covers the nilometer on southern tip of Roda Island in the Nile River at Cairo. The structure is modern but the nilometer dates from 715 AD.[2]
Diagrams of the Nilometer on Roda Island in c.1800

The simplest nilometer design is a vertical column submerged in the waters of the river, with marked intervals indicating the depth of the water.[1] One that follows this simple design, albeit housed in an elaborate and ornate stone structure, can still be seen on the island of Roda in central Cairo[1][2] (30°00′25″N 31°13′30″E / 30.0069°N 31.2250°E / 30.0069; 31.2250 (Rhoda Island nilometer)). This nilometer visible today dates as far back as AD 861, when the Abbasid caliph al-Mutawakkil ordered its construction,[6] overseen by the astronomer Alfraganus. This prior nilometer had been ordered in AD 715 by Usāma b. Zayd b. ʿAdī, who was in charge of collecting the land tax (kharaj) in Egypt for the Umayyad caliph Sulaymān ibn ʿAbd al-Malik.[2][7]

Nilometer on Elephantine Island

The second nilometer design comprises a flight of stairs leading down into the water, with depth markings along the walls.[1] The best known example of this kind can be seen on the island of Elephantine in Aswan,[1] where a stairway of 52 steps leads down to a doorway at the Nile.[8] This location was also particularly important, since for much of Egyptian history, Elephantine marked Egypt's southern border and was therefore the first place where the onset of the annual flood was detected.

The most elaborate design involved a channel or culvert that led from the riverbank – often running for a considerable distance – and then fed a well, tank, or cistern.[1] These nilometer wells were most frequently located within the confines of temples, where only the priests and rulers were allowed access. A particularly fine example, with a deep, cylindrical well and a culvert opening in the surrounding wall, can be seen at the Temple of Kom Ombo, to the north of Aswan.

Historical Usage

While nilometers originated in Pharaonic times, they continued to be used by the later civilizations that held sway in Egypt.[1] Some were constructed in Roman times.[1] The first nilometer on Roda island was constructed by Usama bin Zayd bin Adl in the Caliphate of al-Walid before Jumada II, 96 AH (Feburary 715). Maqrīzī claims a cost of construction of 2,000 ounces (24,000 dirhams). During the Caliphate of Sulayman ibn Abd al-Malik, Usama wrote to the Caliph informing him of the dilapidated state of the nilometer. He later received a reply ordering him to construct a new one, which he did in 97 AH (5th September 715—24 August 716).[9]: 296  Yaqut al-Hamawi in his works claims that in the beginning of year 247 AH (March 861), when Yazid ibn Abd Allah al-Turki was Governor of Egypt, al-Mutawakkil had the 'New' Nilometer constructed and ordered that the privilege of measuring the river 'be taken away from the Christians.' The governor then appointed a man from Basra named Abu'r-Raddad who had emigrated to Egypt and taught the hadith. He died in 266 AH (879/80), with Yaqut claiming 'the supervision of the Nilometer has remained in the hands of his descendants until the present day' (which would have been around 1225 for the author).[9]: 297  Ibn Khallikan gives a different account of the nilometer under al-Mutawwakil's caliphate. According to the account of Ibn Khallikan, a 'pious' Mu'adhdhin in the old Mosque of Amr wished to carve inscriptions in various places of the nilometer. After consulting with Yazid ibn Abd Allah, Sulayman ibn Wahb and Hasan al-Khadim, the Mu'adhdhin asserts to inscript various Qu'ranic passages in the name of al-Mutawakkil. Sulayman ibn Wahb then wrote to the Caliph, who replied in writing to choose verses of the Qu'ran 'most appropriate' to the nilometer and inscript the name of the Caliph.[9]: 297–298 

Ibn Khallikan writes that the architect of the nilometer was Ahmad ibn Muhammad al-Hasib. Abu Ja'far al-Katib and Ibn Abi Usaybi'a mention Ahmad ibn Kathir al-Farghani as being sent to Fustat by al-Mutawakkil to superintend the construction. Abu al-Mahasin Yusuf makes the same statement but calls him Muhammad ibn Kathir al-Farghani. The full name of this man being Abu'l-Abbas Ahmad ibn Muhammad ibn Kathir al-Farghani. Gaston Wiet and Creswell for this reason states that Ibn Khallikan's al-Hasib was hence the same person.[9]: 303 

Between 259 AH (872/873) the virtually independent ruler of Egypt, the first after the Ptolemaic pharaohs, Ahmad ibn Tulun would also have the nilometer restored. Al-Mutawakkil's name being removed from the Kufic inscription of the nilometer.[10] Creswell also claims that the main inscription of the nilometer was probably tampered with by Ibn Tulun, stating "there can be little doubt that it was he who removed the name of the Abbasid Khalif." Ibn Tulun would however refrain from substituting his own name, with Creswell claiming as he did not feel sufficiently secure to do so. The Tulunid Emir during 872-873 would spend 1,000 dinars on works carried out on the nilometer.[9]: 298–299  Consequently, according to Abdul Rofik Bruno, the Nile's irrigation would be enhanced, and agricultural output increased.[11]

Amr ibn al-As after the conquest of Egypt reported to the Caliph Umar that when the Nile rose to 14 cubits there was a sufficient harvest, 16 an abundant harvest, 17 being the most advantageous height of all, and that at 18 one-fourth of Egypt would be inundated and usually be followed by plague. The Baghdad doctor, Abd al-Latif al-Baghdadi who traveled Egypt in 1192-1201 would also relate similar measurements. In the exceedingly low Niles of 1201 and 1202, the nilometer remained dry. In 1201 the year commenced with a rise in 2 cubits, before rising an average 15¹⁶⁄₂₄ cubits. In 1202 the year began with 1½ cubits before rising to 15²³⁄₂₄ cubits.[12]: 31–32  During the Abbasid Period, the nilometer was used to measure the river level and hence determine the rates of tax in Egypt.[13]

In 1937, efforts to unwater and excavate the nilometer led by Kamil Bey Ghalib the Under-Secretary of State for Public Works began, using a new method used by Rothpletz and Lienhard. In this method the mud could be removed completely and the structure examined.[9]: 304 

Aerial view of Aswan Dam, Aswan Egypt

In the 20th century, the Nile's annual inundation was first greatly reduced, and then eliminated entirely, with the construction of the Aswan dams. While the Aswan High Dam's impact on Egypt and its agriculture has been controversial for other, more complex reasons, it has also had the additional effect of rendering the nilometer obsolete.

See also

Wikimedia Commons has media related to Nilometers.
  • The dictionary definition of nilometer at Wiktionary
  • Hunger stone

Notes

  1. ^ a b c d e f g h i j Helaine Elsin (2008). "Nilometer". Encyclopaedia of the History of Science, Technology, and Medicine in ... p. 1753.
  2. ^ a b c d e Brian Fagan (1 August 2010). The Great Warming: Climate Change and the Rise and Fall of Civilizations. Bloomsbury Publishing. p. 167. ISBN 978-1-59691-780-4.
  3. ^ "The Palermo Stone and its unsolved mysteries | www.palermoviva.it" (in Italian). 2021-02-09. Retrieved 2024-03-18.
  4. ^ Danielle Brushaber, Ancient Egypt’s Religious Need For Mathematics, University of Wisconsin-Eau Claire,
  5. ^ a b "Ancient Device for Determining Taxes Discovered in Egypt". History. 2016-05-18. Retrieved 2024-03-18.
  6. ^ Doris Behrens-Abouseif (1992). Islamic Architecture in Cairo: An Introduction. BRILL. p. 51. ISBN 90-04-09626-4.
  7. ^ Ibn ʿAsākir. Tārīkh Madīnat Dimashq. pp. 8:84.
  8. ^ Farid Atiya (2008). Pocket Book of Ancient Egypt. American Univ in Cairo Press. p. 370. ISBN 9789771744399. Retrieved 2017-04-26.
  9. ^ a b c d e f Creswell, K. A. C. (January 1, 1978). Early Muslim Architecture: Umayyads, Early 'Abbasids and Tulunids: II: Early 'Abbasids, Umayyads of Cordova, Aghlabids, Tulunids and Samanids. A.D. 751 - 905, Part 2. Clarendon Press.
  10. ^ yeomans, richard (2006). the art and architecture of islamic cairo. Garnet Pub. Limited. p. 30. ISBN 978-1-85964-154-5.
  11. ^ A, Muhammad Esa Prasastia; Rofiq, Abdul (2022). "Analysis of The Causes of The Disintegration of The Government of The Abbasiyah Dynasty (1000 M-1250 M)". Devotion: Journal of Community Service. 3 (3): 241. ISSN 2797-6068.
  12. ^ Ardagh, J. C. (1889). "Nilometers". Proceedings of the Royal Geographical Society and Monthly Record of Geography. 11 (1): 28–38. doi:10.2307/1800840. ISSN 0266-626X.
  13. ^ "Nilometer | IRCICA". 2020-06-24. Retrieved 2024-04-15.

References

  • Abbeloos, Jean Baptiste; Lamy, Thomas Joseph, eds. (1877). Bar Hebraeus, Chronicon Ecclesiasticum (3 vols). Paris.{{cite book}}: CS1 maint: location missing publisher (link)[full citation needed]
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