PEN

tool for writing or drawing with a coloured fluid, such as ink. The earliest ancestor of the pen probably was the brush used for writing by the Chinese by the 1st millennium BC. The early Egyptians employed thick reeds for penlike implements about 300 BC. A specific allusion to the quill pen occurs in the 7th-century writings of St. Isidore of Seville, but such pens made of bird feathers were probably in use at an even earlier date. They provided a degree of writing ease and control never realized before and were used in Europe until the mid-19th century, when metallic pens and pen nibs (writing points) largely supplanted them. Such devices were known in classical times but little used (a bronze pen was found in the ruins of Pompeii). John Mitchell of Birmingham, Eng., is credited with having introduced the machine-made steel pen point in 1828. Two years later the English inventor James Perry sought to produce more flexible steel points by cutting a centre hole at the top of a central slit and then making additional slits on either side. The inconvenience of having to continually dip a pen to replenish its ink supply stimulated the development of the fountain pen, a type of pen in which ink is held in a reservoir and passes to the writing point through capillary channels. The first practical version of the fountain pen was produced in 1884 by the American inventor L.E. Waterman. Ball-point pens date from the late 19th century. Commercial models appeared in 1895, but the first satisfactory model was patented by Lazlo Biro, a Hungarian living in Argentina. His ball-point pen, commonly called the biro, became popular in Great Britain during the late 1930s, and by the mid-1940s pens of this type were widely used throughout much of the world. The writing tip of a ball-point pen consists of a metal ball, housed in a socket, that rotates freely and rolls quick-drying ink onto the writing surface. The ball is constantly bathed in ink from a reservoir, one end of which is open and attached to the writing tip. Soft-tip pens that use points made of porous materials became commercially available during the 1960s. In such pens a synthetic polymer of controlled porosity transfers ink from the reservoir to the writing surface. These fibre-tipped pens can be used for lettering and drawing as well as for writing and may be employed on surfaces such as plastic and glass.