Open-and-shut mould of iron for making apothecaries' phials, with a phial of clear glass moulded by it, English, 19th century

Open-and-shut mould of iron for making apothecaries' phials, with a phial of clear glass moulded using it, English, 19th century. Mould-blown glass is form of glass produced by blowing molten glass into a mould. This can be a one- piece dip mould or a piece mould in two or more sections. Early moulds were made of fire clay, carved wood or stone. Later metal was used. In industrial glass production mould blowing is the principal means of manufacture.