An Encyclopedia of the History of Technology part 16. This one of a kind encyclopedia presents the entire field of technology from rudimentary agricultural tools to communication satellites in this first of its kind reference source. Following an introduction that discusses basic tools, devices, and mechanisms, the chapters are grouped into five parts that provide detailed information on materials, power and engineering, transportation, communication and calculation, and technology and society, revealing how different technologies have together evolved to produce enormous changes in the course of history | PART ONE MATERIALS the noble metal palladium in the soluble fraction was demonstrated by Wollaston in 1803 and he announced the discovery of another noble metal rhodium in the following year. Ruthenium the sixth and last member of the platinum group was identified by Claus in 1844. Wollaston s process of platinum production was probably the first to utilize a chemical extraction and refining process so controlled that it produced pure fine metallic powder which was specifically intended for consolidation by the powder metallurgical method. He soon became well known for the high quality and ductility of the platinum he produced in this way. In the early years of the nineteenth century large quantities of platinum were needed for the construction of items of chemical plant such as sulphuric acid boilers. Between 1803 and 1820 Wollaston produced about 7000 ounces 197kg of ductile platinum for sulphuric acid boilers alone. Platinum deposits were discovered in the Ural mountains in Russia in 1819 and rich alluvial platinum deposits were found in 1824. In 1825 deposits at Nizhny Tagil north of Ekaterinburg Sverdlovsk were found to yield 100 ounces of gold and platinum per ton per tonne of gravel and Russian platinum continued to satisfy the world s demands until 1917 when political changes encouraged the extraction of this metal from the nickel deposits at Sudbury Ontario see p. 98 . In 1924 platinum was discovered by Dr Hans Merensky in a South African reef near Rustenburg in the Transvaal now known to be one of the world s richest platinum deposits. Vast quantities of copper nickel and cobalt and also gold and silver are also associated with the rich metalliferous vein. The very large cupro-nickel ore deposits discovered at Jinchuan in Ganzhou Province in China in 1958 also contain considerable quantities of both gold and platinum. Rich palladium-platinum deposits have also been found in the Mitu area of Yunan Province which is only about 80km 50 miles away from
