Page 33 - Curriculum Visions Dynamic Book

new pieces of glass – for example, handles – to the work so they could be fused in place.
Coloured glass
By 100 b.c. developments in glassmaking were taking place at Alexandria, Egypt, in North Africa. By using natural earths (which are coloured by metal oxides), glass rods could be made in various colours. Copper oxide produced a green and red glass; iron oxide made black, brown, and green glass; antimony oxide yielded a yellow colour; while manganese produced purple-
coloured glass.
Pieces of these rods then were formed into
patterns just as small pieces of stone are used to make a mosaic floor. The most famous look like flowers and are called millefiori, meaning
“thousand flowers.” In this process the shape of the bowl was made of mud and the glass stuck into
it. The glass and core were then put in an oven so that the glass partly melted and fused together. The
glass was cooled and the mud scraped away. The rough surface of the glass was then ground smooth.
Despite all of these successes, people found it impossible to make flat glass. The only alternative was to use small pieces of glass and to hold them together
(Below) Many modern craftspeople use techniques almost identical to the way glass was blown and moulded thousands of years ago.
(Left and above) By 50 b.c. the technique of glass blowing had
been invented. The bubble of glass could be shaped by rolling it along the ground or blowing it into a mould. This would produce more intricate shapes than with cast glass. Glassblowing enormously speeded up the manufacture of glass. This jar is about 24 cm tall and was made in about the first century a.d.
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