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Text F Metallurgical techniques


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Text F
Metallurgical techniques
Some of the most widespread early metallurgical techniques evolved around the use of copper, the first industrial metal. The earliest use of natural copper involved an extremely limited Stone Age technique by which small, specially selected pieces of metal were made into beads, awls, pins, or hoops by cold forging, a technique that consisted simply of hammering the cold metal. Early attempts to coldhammer small pieces of natural copper were able to give only a limited improvement to such pieces.
The stone-working techniques ( such as simple shaping) found greater success when smiths learned to produce copper of a more malleable form by the process of annealing: exposing the copper to a slow, softening heat. Annealing was a step toward the subsequent melting, or smelting, of cooper. When smiths discovered that melted pieces of copper can form a single puddle that hardens upon cooling, they were able to use small scrap pieces of metal that would otherwise have been unusable
Metals came into limited use 5 500 years ago Copper nuggets and meteoric iron, as well as gold and silver, were also used in that time. Gold, in the form of nuggets was pounded into crude ornaments with a stone hammer. (Unlike copper, gold did not harden appreciably with this pounding, and therefore could not be used to make tools.) Silver nuggets were also used to make rings, bracelets, and other fine ornaments, but not so extensively as gold.
Text G
THE PIONEERS
Karl Benz (1844—1929), the son of a railway engine-driver who died when Karl was two, studied engineering at the Karlsruhe Polytechnic. After various jobs he set up business, with successive partners in a very small way making two-stroke gas engines of his own design in 1880. Although he is entitled to be called the "inventor of the petrol car" he was reluctant to depart from his original design of belt-driven horseless carriage which sold well in 1890s. Other designers were called in, and after 1902 Benz had little influence on the development of the motor car.

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