Professor Paul Nicholson
In 1891-2 Flinders Petrie excavated at Tell el-Amarna, the ancient Akhetaten, capital of the ‘heretic pharaoh’ Akhenaten (1352-1336 B.C.). However, he was interested not only in the history of the site but in its evidence for ancient technologies.
He, accompanied by the young Howard Carter (destined for great things some years later!) unearthed “three or four glass factories, and two large glazing works”. He believed his evidence supported the view that although Egyptians did not invent glass they were able to make it from its raw materials as early as the reign of Akhenaten. His reconstruction of the process became the standard interpretation of early glass making and was reproduced in virtually every book on early glass manufacture.
However, by the 1980s many scholars, influenced by their interpretation of the cuneiform texts known as the Amarna Letters and by the fact that Petrie did not actually find any furnaces for glass had begun to suggest that although glass could be worked by the ancient Egyptians, the actual making of raw glass probably took place in the Near East with Egyptians simply receiving ingots to work into objects.
In 1993, in the hope of determining which view of glass production might be correct I began a project at Amarna excavating in an area which was believed to be near where at least one of Petrie’s glass and glazing works was located. Sadly, Petrie’s publication does not give the actual locations of these sites but there is an area on his plan of the city marked as ‘moulds’ and referring to the fired clay moulds used to produce glazed faience objects. It is clear that these glazed objects were often found alongside glass production and so that was the area chosen for the new work. The site became known as O45.1 after its location in the Amarna grid system.
Before excavation began the site had been subject to geophysical survey carried out by the late Mr. Ian Mathieson whose magnetometry recorded exceptionally high readings consistent with burning at the site. It was hoped that these readings might indicate kilns or furnaces and so it proved to be.
The 1993 season quickly unearthed kilns, believed to be for pottery and faience production, as well as two very large ‘furnaces’ of a type not hitherto known from Amarna or elsewhere in Egypt. These large furnaces were built in a complicated brickwork pattern with walls c.0.5m thick. There was also evidence that they had been given a ‘sacrificial render’ on the interior, a plaster layer which could be removed and replaced when it became vitrified. Enough of the walls remained to suggest that they were originally covered by a domed roof.
There was no evidence to suggest that the furnaces were for metalworking and they did not seem to be intended for lime burning. There was, however, evidence of raw glass from around them and it was tentatively suggested that they might be for the making of glass from its raw materials – soda, lime and silica – a process which requires higher temperatures than the working of pre-prepared glass.
A suggestion to the effect that these were glass furnaces was soundly rejected at a conference on the history of glass held in 1995 on the grounds that they were “too big” and could never have reached the temperatures of c.1100ºC thought necessary for glass production.
In 1996 I, along with Caroline Jackson of Sheffield University, reconstructed one of the furnaces at full size at Amarna. It was charged with a mixture of local sand, which is naturally rich in lime, mixed with plant ashes (derived from seaweed collected at Penarth, as a substitute for other known ash sources) and with a pinch of cobalt to give a deep blue colour. Firing reached a temperature of c.1150ºC and produced an ingot of deep blue glass proving that a furnace of this type could have been used in the making of glass at Amarna. At around the same time the team demonstrated that the size of the glass ingots from a shipwreck at Uluburun (Turkey) were consistent with moulds from Amarna and that their chemistry also matched with Egyptian ingredients. Whilst Petrie’s famous reconstruction of the glassmaking process at Amarna proved to be wrong, his view that raw glass was made at the site has been proven to be correct, irrespective of whether it was made in furnaces such as that which was replicated.
In 2000 the Corning Museum of Glass, U.S.A. built a reproduction of one of the Amarna furnaces as part of their origins of glass display. Subsequent work has suggested that the Egyptians were making glass still earlier than Amarna and that although some glass was imported to the country it was also being exported. The pattern of trade and technology in the bronze age is more complicated and more interesting than might have been imagined!