The revolutionary discovery that glass could be blown and expanded to any shape was made in the third quarter of the 1st century BC, in the Middle East along the Phoenician coast. Glassblowing soon spread and became the standard way of shaping glass vessels until the 19th century. The necessary tool is a hollow iron pipe about 1.2 m (4 ft) long with a mouthpiece at one end. The glassblower, or gaffer, collects a small amount of molten glass, called a gather, on the end of the blowpipe and rolls it against a paddle or metal plate to shape its exterior (marvering) and to cool it slightly. The gaffer then blows into the pipe, expanding the gather into a bubble, or parison. By constantly reheating at the furnace opening, by blowing and marvering, the gaffer controls the form and thickness. Simple hand tools such as shears, tongs (pucellas), and paddles are used to refine the form, often while the glassblower sits in the special "glassmaker's chair", one with extended arms to support the blowpipe. Blown glass can also be shaped with moulds: part-size moulds pattern the gather, which is then removed and blown to the desired size. Full-size moulds into which the gather is entirely blown impart size, shape, and decoration. Additional gathers may be applied and manipulated to form stems, handles, and feet, or they may be trailed on and tooled for decoration. A shaped bubble can be "flashed" with colour by dipping it into molten glass of contrasting colour. To make cased glass, a gather is placed within, and fused to, one or more layers of differently coloured glass. For finish work and fire polishing at the mouth of the furnace, the gather is transferred to a solid iron rod called a pontil, applied opposite the blowpipe, which is then removed. When the pontil is cracked off it leaves a "pontil mark" that may be later ground or polished away.