Water clocks were used as time keeping instruments in ancient Egypt from at least the New Kingdom until the end of pharaonic history. Most of the surviving full-sized water clocks are made of stone and are inscribed inside and out. All but one of them are 'outflow' water clocks, meaning that time was indicated by the water level falling past scale marks as the water ran out of the vessel. The remaining one is apparently an inflow water clock (water level rising past scale marks as the water ran into the vessel). Most water clocks have been found in pieces; fragments of the same vessel may currently be in different collections. The list below does not include smaller water clocks without scales, which may be models rather than real vessels.

The ID column gives a sequential number for each vessel (fragments are referred to by an additional lower-case letter, Fr.) based on the system of Lodomez (2007). Most objects are poorly provenanced, but the inscribed name gives a date reference. The exterior decoration of outflow water clocks sometimes included an astronomical representation (AR). These vessels are cross-referenced to the relevant page in the astronomical representations section of the database in the AR? column.

Click on the ID number to go to the description of the water clock.

Outflow Water Clock


AR?FragmentCurrent locationCatalogue No.Inscribed to
WCO 1 Yes   Egyptian Museum, Cairo JE 37525 Amenhotep III
WCO 2 Yes   Egyptian Museum, Cairo JE 67096 Nekau II
WCO 3     a British Museum, London BM EA933 Alexander the Great
b Musée du Louvre, Paris E 30890
c Ägyptisches Museum, Berlin ÄM 30508
d In private collection -
WCO 4    a Hermitage, Saint Petersburg ДВ-2507a Alexander the Great
b Museo Nazionale, Naples 2327
WCO 5     Brooklyn Museum, New York 57.21.1 Alexander the Great
WCO 6     British Museum, London EA938 Philip Arrhidaeus
WCO 7    a Museo Egizio, Turin Supp. 8  
b Musées royaux d'Art et d'Histoire, Brussels E.04782  
WCO 8  Yes   Pushkin Museum, Moscow I.1.a.5955  
WCO 9     Ephesus Unknown  
WCO 10 Yes a Musée du Louvre, Paris N 664 Ptolemy II
b Thorvaldsens Museum, Copenhagen H351
WCO 11     Museo Barracco, Rome MB 27 Ptolemy II
WCO 12     Hermitage, Saint Petersburg ДВ-2507b  
WCO 13     Lost (was in Ägyptisches Museum, Berlin) ÄM 19556 Hadrian
WCO 14     Museo Archeologico, Florence 2613  
WCO 15     Greco-Roman Museum, Alexandria P.9619  
WC? 16     Museo Egizio, Turin Supp. 3524  
WCO 17 Yes   Museo Archeologico, Florence 12290  
WCO 18    a Petrie Museum, London UC55487 ?Nectanebo
b In private collection -
WCO 19     Oriental Institute Museum, Chicago E16875  
WCO 20     Capitoline Museum, Rome -  
WCO 21 Yes   Oriental Institute Museum, Chicago A7125 Ptolemy II
WC? 22     British Museum, London EA21736  
WC? 23     Lost (was found in Rome) -  
Inflow Water Clock
IDProvenanceAR?Current locationCatalogue number
WCI 1 Edfu No Egyptian Museum, Cairo TR
ID in this catalogue WCO 1
Type Outflow water clock
Current Location Egyptian Museum, Cairo
Catalogue Numbers JE 37525
Provenance Burial cachette in the court of the seventh pylon at Karnak (Legrain (1906), 65)
Date Amenhotep III, 18th Dynasty, New Kingdom

External: height 34.5 cm; upper diameter 46 cm; lower diameter 26 cm

Internal: height 30.6 cm; upper diameter 44.4 cm; lower diameter 23 cm

Thickness of material: 2 cm (average)

(After Mengoli (1989))

Material Calcite (alabaster) or travertine (Müskens (2017))
Condition Mostly complete - reassembled from fragments

As this is the most complete example of an Egyptian water clock, JE 37525 is widely referred to in passing throughout Egyptological scholarship. For the sake of brevity, this following list includes only work that provides significant detail:

Legrain (1906); Daressy (1915); Sloley (1924, 1931); Pogo (1936b); Chatley (1940); Neugebauer & Parker (1969); Leblanc and Nelson (1976); von Mackensen (1978); Curto (1984); Dorner (1985); Cotterell, Dickson & Kamminga (1989);  Mengoli (1989); Mills & Symons (2000); Müskens (2017)

External registers 3
External upper band of text Not present
External lower band(s) of text Not present
Exterior Astronomical Diagram Yes, AR1 Water clock (Amenhotep III)
Rim Civil month labels around the rim of the vessel, labelling the twelve columns of hour-marks on the interior surface by season and month.
Interior markings Twelve columns of small round holes, each corresponding with a month name on the rim. Below each of these vertical scales is a raised relief symbol of either an anx or a Dd-pillar which alternate around the interior of the vessel.
Other features The astronomical diagram's upper two registers are interrupted by scene of  Amenhotep III offering to Re-Horakhty (the Sun) and Thoth (the Moon).

This is the earliest surviving example of an ancient Egyptian outflow water clock. Originally discovered in pieces in Karnak, it has been restored and is on display in Cairo. The incised decoration has remnants of inlay in semi-precious stones.

See also the entry in: Schomberg, A., Berlin Waterclock Project, ID 15 Karnak, 2019, Edition Topoi, DOI: 10.17171/2-10-7. (Berlin cast of this object is ID 1.)


The majority of images found online (by Googling for "Karnak clepsydra" or similar) are of replicas or reconstructions. The Global Egyptian Museum website has one photo here accompanying a record here.


ID in this catalogue WCO 18
Type Outflow water clock vessel, represented by two extant fragments
Current Location

Fragment a: Petrie Museum, London

Fragment b: Sold at Sotheby's, now presumably in a private collection

Catalogue Numbers

Fragment a: UC55487

Fragment b: N/A

Provenance Athribis/Mostai in the Nile Delta (Sotheby's listing), from the identification of an epithet of Thoth on the Petrie Museum fragment
Date Dynasty 30, ?Nectanebo 

Fragment a (from the Petrie Museum catalogue): height 12.7 cm; width 18.8 cm; thickness 4.5 cm

Fragment b (from the Sotheby's catalogue): height 13.8 cm; depth 3.6 cm

Material Basalt


The two fragments show careful manufacture but together make up very little of the original vessel. Both fragments come from the area near the bottom of the interior hour scales.

Online Petrie Museum catalogue can be visited here.

Sotheby's sale catalogue listing here .

External registers Unknown
External upper band of text Unknown
External lower band(s) of text Partially preserved: Fragment a includes "Thoth son of the two Lords, he who emerges from the forehead". A vertical label on fragment b: "To consecrate the bread for his father who ensures that he is endowed with life" (Sotheby's sale catalogue listing)
Exterior Astronomical Diagram The lower parts of the pharaoh and deities appear on both fragments, but it is unclear whether there were upper registers with astronomical material above.
Rim Not preserved
Interior markings Columns of dots, with Dd and wAs symbols underneath
Other features  

Fragment b sold for 60,000 USD on 12 December 2013 at Sotheby's, New York.

See also the entries in:

Schomberg, A., Berlin Waterclock Project, ID 40 Petrie Museum, 2019, Edition Topoi, DOI: 10.17171/2-10-35 [Fragment a]
Schomberg, A., Berlin Waterclock Project, ID 23 Private Collection, 2019, Edition Topoi, DOI: 10.17171/2-10-16 [Fragment b]


Fragment b: Sotheby's sale catalogue listing has intererior and exterior views here with high resolution zoomable images.

Fragment a: Exterior view, courtesy of The Petrie Museum of Egyptian Archaeology UCL

UC55487 Exterior.jpg

Fragment a: Interior view, courtesy of The Petrie Museum of Egyptian Archaeology UCL

UC55487 Interior.jpg


ID in this catalogue WCO 2
Type Outflow water clock 
Current Location Egyptian Museum, Cairo
Catalogue Number(s) JE 67096 
Provenance Tanis
Date Necho II, 26th Dynasty, Late Period, based on the appearance of the prenomen wHm-ib-ra

The dimensions of this fragment remain unpublished, however Neugebauer and Parker (EAT 3) provide an estimation of the complete vessel to be: height: 37 cm; upper diameter 57 cm; lower diameter 52 cm.

Material ?Limestone


Incomplete. Four remaining and adjacent fragments have been joined.

Kircher (1654)

Montet (1946)

Schott (1950)

Neugebauer & Parker (1969)

External registers A unique arrangement such that 4 distinct bands or subregisters are visible.
External upper band of text Unknown. Top preserved register contains lunar months.
External lower band(s) of text Unknown. Lowest preserved register contains hours of the night.
Exterior Astronomical Diagram Yes. See here.
Rim Not preserved.
Interior markings According to Montet (1946), the interior is divided by bands of regular dots which end with the was sceptre or ankh sign.
Other features The outflow hole of this vessel is on one of the remaining fragments and is located between the legs of a seated baboon. 

This water clock is the only known example to contain (at least) four registers. The first contains the names of the lunar months. The second register contains the names of decans with their associated deities in a subregister below. A vignette of the pharaoh and Amun spans some of the second and third registers, while the remaining portion of the third contains a line of a text. The fourth register seems to have contained the hours of the day and night.

See also the entry in: Schomberg, A., Berlin Waterclock Project, ID 2 Necho, 2019, Edition Topoi, DOI: 10.17171/2-10-12


Details of the exterior decoration can be found in the Astronomical Respresentations section of this database here.


Montet (1946) has a line drawing. Figure 9 in Egyptian Astronomical Texts vol 3 reproduces Montet's drawing.