Crown Glass
"The Making of a Crown Glass Disk
Five craftsmen were involved in this process: The first glassmaker gathers glass on the blow pipe in several steps and then blows the glob of glass into a sphere and rolls it into a cylindrical shape (1). An assistant takes the blow pipe and passes it onto a blower; he heats the glass, blows it, and flattens one side of the form (2). A helper attaches a pontil, a solid iron rod, to the glass and the blow pipe is cracked off the piece (3). The hole created by this break is used to enlarge the glass form into a crown-like shape. After intensively heating the piece, an experienced glass blower spins the softened glass into a circular sheet (5). This is placed in a bed of sand. The pontil is then removed and this leaves a characteristic mark in the middle of the disk, the bull's eye."
[Don't believe anyone who tries to tell you that you can observe the slow motion of glass in the increased thickness at the bottom of old panes of glass. Its not true- sometimes these old panes are thicker at the bottom, but sometimes you can find them thicker at the top- the difference is a consequence of the manufacturing process and not of any flow process in the solid glass].
Crown Glass
"The Making of a Crown Glass Disk
Five craftsmen were involved in this process: The first glassmaker gathers glass on the blow pipe in several steps and then blows the glob of glass into a sphere and rolls it into a cylindrical shape (1). An assistant takes the blow pipe and passes it onto a blower; he heats the glass, blows it, and flattens one side of the form (2). A helper attaches a pontil, a solid iron rod, to the glass and the blow pipe is cracked off the piece (3). The hole created by this break is used to enlarge the glass form into a crown-like shape. After intensively heating the piece, an experienced glass blower spins the softened glass into a circular sheet (5). This is placed in a bed of sand. The pontil is then removed and this leaves a characteristic mark in the middle of the disk, the bull's eye."
[Don't believe anyone who tries to tell you that you can observe the slow motion of glass in the increased thickness at the bottom of old panes of glass. Its not true- sometimes these old panes are thicker at the bottom, but sometimes you can find them thicker at the top- the difference is a consequence of the manufacturing process and not of any flow process in the solid glass].