A nilometer was a structure for measuring the
Nile
The Nile, , Bohairic , lg, Kiira , Nobiin language, Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered ...
River's clarity and water level during the
annual flood season.
[ There were three main types of nilometers, calibrated in ]Egyptian cubits
The cubit is an ancient unit of length based on the distance from the elbow to the tip of the middle finger. It was primarily associated with the Sumerians, Egyptians, and Israelites. The term ''cubit'' is found in the Bible regarding No ...
: (1) a vertical column, (2) a corridor stairway of steps leading down to the Nile, or (3) a deep well with culvert
A culvert is a structure that channels water past an obstacle or to a subterranean waterway. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. In the United Kingdom ...
.[ 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.]
Nilometers originated in Pharaonic
Pharaoh (, ; Egyptian: '' pr ꜥꜣ''; cop, , Pǝrro; Biblical Hebrew: ''Parʿō'') is the vernacular term often used by modern authors for the kings of ancient Egypt who ruled as monarchs from the First Dynasty (c. 3150 BC) until the ...
times, were also built in Roman times, and were used until the Aswan Dam
The Aswan Dam, or more specifically since the 1960s, the Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. Its significance largely eclipsed the previous Aswan L ...
rendered them obsolete in the 1960s.
Description
Between July and November, the reaches of the Nile running through Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediter ...
would burst their banks and cover the adjacent floodplain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...
. When the waters receded, around September or October, they left behind a rich alluvial deposit
Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...
of exceptionally fertile black silt over the croplands. The ''akhet'', or Season of the Inundation
The Season of the Inundation or Flood ( egy, Ꜣḫt) was the first season of the lunar and civil Egyptian calendars. It fell after the intercalary month of Days over the Year ('). and before the Season of the Emergence ('). In the modern Copt ...
, 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
A famine is a widespread scarcity of food, caused by several factors including war, natural disasters, crop failure, Demographic trap, population imbalance, widespread poverty, an Financial crisis, economic catastrophe or government policies. Th ...
, and too much flood water would be equally disastrous, washing away much of the infrastructure built on the flood plain. Records from AD 622999 indicate that, on average, 28% of the years saw an inundation that fell short of expectations.
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.
Designs
The simplest nilometer design is a vertical column submerged in the waters of the river, with marked intervals indicating the depth of the water.[
One that follows this simple design, albeit housed in an elaborate and ornate stone structure, can still be seen on the island of ]Rhoda
''Rhoda'' is an American television sitcom created by James L. Brooks and Allan Burns starring Valerie Harper that originally aired on CBS for five seasons from September 9, 1974, to December 9, 1978. It was the first spin-off of ''The Mary Tyle ...
in central Cairo
Cairo ( ; ar, القاهرة, al-Qāhirah, ) is the capital of Egypt and its largest city, home to 10 million people. It is also part of the largest urban agglomeration in Africa, the Arab world and the Middle East: The Greater Cairo metro ...
This nilometer visible today dates as far back as AD 861, when the Abbasid
The Abbasid Caliphate ( or ; ar, الْخِلَافَةُ الْعَبَّاسِيَّة, ') was the third caliphate to succeed the Islamic prophet Muhammad. It was founded by a dynasty descended from Muhammad's uncle, Abbas ibn Abdul-Muttalib ...
caliph al-Mutawakkil
Abū al-Faḍl Jaʿfar ibn Muḥammad al-Muʿtaṣim bi-ʾllāh ( ar, جعفر بن محمد المعتصم بالله; March 822 – 11 December 861), better known by his regnal name Al-Mutawakkil ʿalā Allāh (, "He who relies on God") was t ...
ordered its construction, overseen by the astronomer Alfraganus
Abū al-ʿAbbās Aḥmad ibn Muḥammad ibn Kathīr al-Farghānī ( ar, أبو العبّاس أحمد بن محمد بن كثير الفرغاني 798/800/805–870), also known as Alfraganus in the West, was an astronomer in the Abbasid court ...
. It was built on a site occupied by an earlier specimen which was seen by the Syrian Orthodox patriarch Dionysius of Tel Mahre
Dionysius I Telmaharoyo (Latin: ''Dionysius Telmaharensis'', Syriac: ܕܝܘܢܢܘܣܝܘܣ ܬܠܡܚܪܝܐ, Arabic: مار ديونيسيوس التلمحري), also known as Dionysius of Tel Mahre, was the Patriarch of Antioch, and head of the Syr ...
in 830. 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
The Umayyad Caliphate (661–750 CE; , ; ar, ٱلْخِلَافَة ٱلْأُمَوِيَّة, al-Khilāfah al-ʾUmawīyah) was the second of the four major caliphates established after the death of Muhammad. The caliphate was ruled by the ...
caliph Sulaymān ibn ʿAbd al-Malik.
The second nilometer design comprises a flight of stairs leading down into the water, with depth markings along the walls.[
The best known example of this kind can be seen on the island of ]Elephantine
Elephantine ( ; ; arz, جزيرة الفنتين; el, Ἐλεφαντίνη ''Elephantíne''; , ) is an island on the Nile, forming part of the city of Aswan in Upper Egypt. The archaeological sites on the island were inscribed on the UNESCO ...
in Aswan
Aswan (, also ; ar, أسوان, ʾAswān ; cop, Ⲥⲟⲩⲁⲛ ) is a city in Southern Egypt, and is the capital of the Aswan Governorate.
Aswan is a busy market and tourist centre located just north of the Aswan Dam on the east bank of the ...
,[ where a stairway of 52 steps leads down to a doorway at the Nile.] 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.[ These nilometer wells were most frequently located within the confines of ]temple
A temple (from the Latin ) is a building reserved for spiritual rituals and activities such as prayer and sacrifice. Religions which erect temples include Christianity (whose temples are typically called churches), Hinduism (whose temples ...
s, 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
The Temple of Kom Ombo is an unusual double temple in the town of Kom Ombo in Aswan Governorate, Upper Egypt. It was constructed during the Ptolemaic dynasty, 180–47 BC. Some additions to it were later made during the Roman period.
Architectur ...
, to the north of Aswan.
Usage
While nilometers originated in Pharaonic times, they continued to be used by the later civilizations that held sway in Egypt.[ Some were constructed in Roman times.][
In the 20th century, the Nile's annual inundation was first greatly reduced, and then eliminated entirely, with the construction of the ]Aswan dam
The Aswan Dam, or more specifically since the 1960s, the Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. Its significance largely eclipsed the previous Aswan L ...
s. While the Aswan High Dam
The Aswan Dam, or more specifically since the 1960s, the Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. Its significance largely eclipsed the previous Aswan Lo ...
'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
*
*Hunger stone
A hunger stone (German: ''Hungerstein'') is a type of hydrological landmark common in Central Europe. Hunger stones serve as famine memorials and warnings and were erected in Germany and in ethnic German settlements throughout Europe in the 15th ...
Notes
References
*
{{Authority control
Architecture in Egypt
Measuring instruments
Nile
Water supply
Hydrology instrumentation