Faience: the ceramic technology of ancient Egypt

Faience: the ceramic technology of ancient Egypt - by Amelia Carolina Sparavigna, Archaeogate, 12-02-2012 ,

The term "faience" is commonly referred to a glazed earthenware, the use of which spread in Europe during the Renaissance from France and Italy [1]. The term was derived from Faenza, the town in Italy, where the glazed earthenware was mainly produced. The other name often used for this earthenware is "majolica". Majolica itself had a long tradition in the North African and Near East Islamic production of ceramic. In the 19th century, European archaeologists used the misleading name of "Egyptian faience" to designate the siliceous ceramics produced in the ancient Egypt. The ancient faience was a completely different material created to imitate the gloss and colour of gems and precious stones. This material started to be used in jewellery in Egypt and the Near East, about the fourth millennium BC [2], that is, during the predynastic age.

More at:
http://porto.polito.it/2489310/2/Faience_acs.pdf

At the Egyptian Museum, Torino

Egyptian portrait

Portrait

Egyptian Museum - Torino

How to measure the stair angle

Use a protractor (available at most hardware stores) to determine this angle.

Lay a straightedge across a minimum of 3 stair nosings. Put your universal protractor on the straightedge and measure the angle.  Note that the more stair nosings you have under the straightedge, the more accurate the angle will be. In the case that the run of stairs is very long, measure the stair angle at 2 or 3 places along the run to check that the angle remains constant along the full run.

I am proposing that Kha the architect at Deir El-Medina, Egypt, supervisor of the projects of three kings of the 18th Dynasty used his protractor to check the inclination of stairs for instance. You can see it at the Egyptian Museum of Torino. Read more at http://stretchingtheboundaries.blogspot.com/2011/08/khas-protractor.html

A modern universal protractor for building  is that shown in the following figure.

Kha

Kha, the architect

Museo Egizio, Torino

Back to Kha's protractor

In the post "Kha's protractor", I have discussed an object found in the tomb of  an ancient egyptian architect, Kha.  It can be used to measure angles.Plums, levels, protractors , compasses and so on are instruments for surveying. See http://en.wikipedia.org/wiki/Surveying and the table http://en.wikipedia.org/wiki/File:Table_of_Surveying,_Cyclopaedia,_Volume_2.jpg
In this table there is the image of a compass rose. We can start from it and go back to the Kha's rose.

Kha's protractor

Kha was an architect at Deir El-Medina, Egypt, supervisor of some projects completed during the reigns of three kings of the 18th Dynasty (approximately 1440-1350 BC). Buried with his wife Merit, the items of their tomb are exposed at the Egyptian Museum, Torino. The paper at http://arxiv.org/abs/1107.4946 describes some devices of the ancient Egypt masonry (cubits, cords, plumb, levels and squares), that Kha used during his activity. An object among those found in his tomb could be used a protractor.

The figure shows an object from the Kha’s Tomb supposed to be the case of a balance scale, or the scale itself as reported by the corresponding label. In a previous preparation of the items of Kha’s Tomb, it was possible to see the front and back of the object. They are the same, with the same complex decoration.

The tool has a complex decoration, that suggested me the case could be used as a protractor, to determine directions and measure angles. The detail of decoration is shown in the following figure. 

 We see the 16-fold symmetry of a compass rose with 16 leaves as an inner decoration. Outside this rose there is a polygonal line with 18 corners and then 36 sides. In the inner decoration we can see the fraction 1/16 corresponding to one leaf. The Egyptian knew  and used the fractions as the sum of distinct unit fractions. That is, a fraction was written as a sum of fractions, each fraction having a numerator equal to 1 and a denominator equal to a positive  integer. Every positive rational number can be represented by an Egyptian fraction. In this ancient system of calculus, the Eye Of Horus defined the Old Kingdom number one, such as, 1 =  1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64, rounded-off at the six-term. A 1/64 is needed to have the exact value 1. The separated parts of the Eye of Horus were used to write describe the fractions. May be, Kha used the balance case for calculations, or simply as a protractor when he was using a plumb, a level or a scale, to find vertical or equilibrium positions, but also to measure the deviation from vertical or horizontal directions. 
Is there anything we can tell about number 36, the number of corners of the external decoration of the architect’s case? Let us remember that the Egyptians has the Decans, 36 groups of stars which rise in succession from the horizon due to the earth rotation. The rising of each decan marked the beginning of hours of the night. In the ancient Egypt, the decans were used as a sidereal clock beginning by at least the 9th or 10th Dynasty (ca 2100 BC). Probably, the object found in the Kha’s tomb had simply a geometrical decoration, such as that on another object of the tomb, which seems to be a “rose of direction”. 

The use of 1/16 fraction, the coincidence of the number of corners  with that of decans, and the fact that the decoration was engraved on the instrument of an architect, suggest me that this object had been used as a protractor instrument with two scales, one based on Egyptian fractions, the other based on decans. 
Assuming this tool used to evaluate angles, let me show a possible set-up to measure the angle of an  inclined plane. Note that the case has a lid. Let us imagine to remove the lid; the case has a perfectly linear side, that can be put on a smooth surface, as shown in the following figure. 

(http://arxiv.org/abs/1107.4946)

When the surface is horizontal, using a plumb to have the vertical direction, one of the directions of the rose of the case coincides with the direction of the plumb (the line between leaves 1-16 or 8-9 seems to be perpendicular to the side of the case). If the surface is inclined, the direction of the rose is inclined 
forming a certain angle with respect to the vertical. This angle has the same value of the angle of the inclined plane.  
Geometry originated as a practical science, to measure lengths, surfaces and volumes. In my opinion, Kha could have used his tool, with the contemporary use of a plumb to have a reference direction, to create a set-up able to provide a practical measurement of inclination. The Kha’s protractor could be one of the first devices to measure angles. 



References 
TT8, http://en.wikipedia.org/wiki/TT8
Turin Egyptian Museum: the tomb of Kha 
Deir El Medina: The Painted Tombs, Christine Hobson, Exploring the World of the Pharaohs: A 
complete guide to Ancient Egypt, Thames & Hudson, 1993. 
Building in Egypt; Pharaonic Stone Masonry, Dieter Arnold, Chapter 6, Tools and their 
applications, New York and Oxford, 1991 
Cubits,  http://en.wikipedia.org/wiki/Cubit
E. Robens and R.S.H. Mikhail, The ancient Egyptian balance, Thermochimica Acta, Volume 
82(1), 1 December 1984, Pages 63-80. 7. Egypt Plumb Bobs, Wolfgang Ruecher, Wolf’s Plumb Bob News, Issue 02, Feb.2010,  
http://www.plumbbob.de/media//DIR_42117/DIR_120101/309a7eac7359df18ffff818cac14422e.pdf
http://en.wikipedia.org/wiki/Eye_of_Horus
http://en.wikipedia.org/wiki/Egyptian_fraction
http://en.wikipedia.org/wiki/Decans

Scarab seals

"Ancient Egyptian scarabs were popular amulets in ancient Egypt. According to ancient Egyptian myths, the sun  rolls across the sky each day and transforms bodies and souls. Modeled upon the Scarabaeidae family dung beetle, which rolls dung into a ball for the purposes of eating and laying eggs that are later transformed into larva, the scarab was seen as an earthly symbol of this heavenly cycle. This came to be iconographic, and ideological symbols were incorporated into Ancient Egyptian society."

From Wiki

Heart-scarab with a decoration on the back

(Egyptian Museum, Torino)

See my book

http://www.scribd.com/doc/42000776/Ancient-Egyptian-Seals-and-Scarabs-by-A-C-Sparavigna-2009

Painted egyptian ostraca

Painted ostraca

Egyptian Museum, Torino

The first ever ancient Egyptian epigraphy

"Following the relocation of the artefacts, a team from Yale University, the University of Bologna and the Provinciale Hogeschool Limburg, Belgium, has completed the first epigraphic and digital record of a site near Nag El-Hamdulab on the west bank of the Nile, north of Aswan. The site was discovered nearly half a century ago by the famous Egyptian Egyptologist Labib Habachi. Minister of State for Antiquities Zahi Hawass said this new and thorough study has brought to light a previously unknown Early Dynastic cycle of royal images and an early hieroglyphic inscription. This work was carried out by the Aswan-Kom Ombo Archaeological Project (AKAP)..., lead by Maria Carmela Gatto and Antonio Curci, ... Now in its seventh season, the project aims to survey and rescue the archaeology of the region between Aswan and Kom Ombo, in the southern part of Upper Egypt. Gatto said that this group of images and the short inscription—carved around 3200 BCE, at the dawn of the dynastic period—record the earliest depiction of a royal Jubilee complete of all the elements known from later documents: an Egyptian ruler wearing a recognizable crown of Egypt; “the following of Horus”; and the royal court as known it is known to have been in Early Dynastic accounts such as the Palermo Stone."

The first ever ancient Egyptian epigraphy - Ancient Egypt - Heritage - Ahram Online

Workers in Egypt

Museo Egizio - Torino

Faience of Egypt

"Egyptian faience is a non-clay based ceramic displaying surface vitrification which creates a bright lustre of various blue-green colours. Having not been made from clay it is often not classed as pottery. It is called "Egyptian faience" to distinguish it from faience, the tin glazed pottery associated with Faenza in northern Italy. Egyptian faience, both locally produced and exported from Egypt, occurs widely in the ancient world, and is well known from Mesopotamia, the Mediterranean and in northern Europe as far away as Scotland." Wiki

Faience bowl blue-glazed decorated with lotus flowers and the face of the goddess Hathor, symbol of rebirth are the decoration.

Faience. Provenance unknown. New Kingdom, dynasty XVIII-XX (1350-1070 B.C.)
Egyptian Museum, Turin.

Weighing of the Heart

"In Egyptian religion, the heart was the key to the afterlife. It was conceived as surviving death in the nether world, where it gave evidence for, or against, its possessor. It was thought that the heart was examined by Anubis and the deities during the Weighing of the Heart ceremony. If the heart weighed more than the feather of Maat, it was immediately consumed by the monster Ammit."
Wiki

Egyptian Museum Torino

Four sons of Horus

Statuette dei quattro figli di Horus: Duamutef, a testa di sciacallo, Hapi, a testa di babbuino, Qebehsebuf, a testa di falco, Amset, a testa umana erano i protettori delle viscere del defunto, XXV-XXXI dinastia. Statuettes of the four sons of Horus:  Duamutef, jackal headed, Hapi, baboon headed,  Qebehsebuf, falcon headed, and human headed Amset, protectors of the deceased's viscera,  Dinasty XXV-XXXI
(712-332 BC)

Earliest Roman basilica found outside Alexandria - Ahram Online

"At Al-Baron area in Semouha district, south of Alexandria, an Egyptian archaeological mission has discovered several significant monuments and artefacts that will help in the writing of the history of the area.

During excavations, archaeologists uncovered the earliest Roman civil basilica yet found on top of a Ptolemaic temple dedicated to the three Alexandria deities (Isis, Serapis, Harpocrates) along with a collection of terracotta statues."
Earliest ever civil Roman basilica found outside Alexandria - Greco-Roman - Heritage - Ahram Online

Khufu’s second solar boat revealed

"Today, hundreds of foreign and Egyptian journalists along with photographers, cameramen and TV presenters flocked to the Giza Plateau, where Minister of State for Antiquities Zahi Hawass, Chargé d’Affaires at the Japanese Embassy to Egypt Masami Kinefuchi, and the chief executive representative of the Nitori Holding Company, Akio Nitori, unveiled King Khufu’s second solar boat. This boat was first discovered in 1954 by Egyptian architect and archaeologist Kamal El-Malakh with fellow archaeologist Zaki Nour during routine cleaning at the southern side of Khufu’s Great Pyramid. The first pit was found under a roof of 41 limestone slabs. Removing one of these slabs, a cedar boat, completely dismantled but arranged in the semblance of its finished form, was found along with layers of mats, ropes, instruments made of flint and some small pieces of white plaster with 12 oars, 58 poles, three cylindrical columns and five doors."
Khufu’s second solar boat revealed - Ancient Egypt - Heritage - Ahram Online