Came across this on a blog called futilitycloset, it’s full of quirky goodness but this just needed more investigation.

The Mystery Slab of Beth She’Arim

Huge glass slab made circa 400AD

Making large sheets of glass is hard. Making a 2m by 3½m by 45cm slab of glass is awesomely hard to make. Even now this would be a big project. But the details of when, where and the theories on how this one was made are quite fascinating.

9 tons of glass taking maybe 5-10 days at 1100 degC probably needing 20 tonnes of fuel to fire.

Read on at the Corning Museum of Glass.

There’s a PDF file too, glass-slab__byz76365, from the Centre for Byzantine, Ottoman and Modern Greek Studies at the University of Birmingham (UK). Read from the sixth page of the PDF, labelled “34”. They give details about the glass trade at the time, different places and modes of manufacture and distribution as well as final use.