Composition, production and procurement of glass at San Vincenzo: an early medieval monastic complex in southern Italy

136 glasses from the ninth-century monastery of San Vincenzo and its workshops have been analysed by electron microprobe in order to situate the assemblage within the first millennium CE glass making tradition. The majority of the glass compositions can be paralleled by Roman glass from the first to third centuries, with very few samples consistent with later compositional groups. Colours for trailed decoration on vessels, for vessel bodies and for sheet glass for windows were largely produced by melting the glass tesserae from old Roman mosaics. Some weakly-coloured transparent glass was obtained by re-melting Roman window glass, while some was produced by melting and mixing of tesserae, excluding the strongly coloured cobalt blues. Our data suggest that to feed the needs of the glass workshop, the bulk of the glass was removed as tesserae and windows from a large Roman building. This is consistent with a historical account according to which the granite columns of the monastic church were spolia from a Roman temple in the region. The purported shortage of natron from Egypt does not appear to explain the dependency of San Vincenzo on old Roman glass. Rather, the absence of contemporary primary glass may reflect the downturn in long-distance trade in the later first millennium C.E., and the role of patronage in the “ritual economy” founded upon donations and gift-giving of the time

An archaeological and chemical investigation of 11th–12th centuries AD glasses from Zeyrek Camii (the Pantokrator church) in Byzantine Constantinople

Fifteen glass window, vessel and glass chunk samples collected from the western part and substructure of Zeyrek Camii (the Pantokrator Church) in Istanbul were analysed using an electron microprobe (EPMA). The results show that these samples are all soda-lime-silica glass. Based on the major and minor elements, two different compositional groups were identified and evidence of recycling/mixing was also revealed. Group 1 is plant ash-based glass, while group 2 is the result of mixing natron and plant ash glasses. Comparison with contemporary glass objects from the eastern Mediterranean shows that these glasses probably derived from at least two different production zones in the Syro-Palestinian region: (1) possibly Damascus or Banias and (2) possibly Tyre. The authors suggest that the trading of plant ash glasses between the Byzantine Empire and the Middle East in the 11th–12th centuries AD was well established based on the archaeological and scientific evidence

New insights into Byzantine glass technology from loose mosaic tesserae from Hierapolis (Turkey): PIXE/PIGE and EPMA analyses

peer reviewe

Lenses in Renaissance Science

Lenses – curved pieces of glass that can focus light to create magnified images of objects – must be included among those essential and irreplaceable instruments whose use helped to view reality in an unprecedented way. For example, lenticular artifacts such as telescopes, microscopes, and eyeglasses, literally allowed to focus a new image of the world, up to persuade mankind on an optical basis that – as Shakespeare’s Hamlet said – “there are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.

Homocentrism

Lenses – curved pieces of glass that can focus light to create magnified images of objects – must be included among those essential and irreplaceable instruments whose use helped to view reality in an unprecedented way. For example, lenticular artifacts such as telescopes, microscopes, and eyeglasses, literally allowed to focus a new image of the world, up to persuade mankind on an optical basis that – as Shakespeare’s Hamlet said – “there are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.