Anthracite latter in two or three sizes, all three being above in (38 mm) size on round-hole screens. High grade (HG) and ultra high grade (UHG) anthracite are the highest grades of anthracite coal. They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles). High grade and ultra high grade anthracite are harder than standard grade anthracite, and have a higher relative density. An example of a chemical formula for high-grade anthracite would be CHONS, representing 94% carbon. UHG anthracite typically has a
What is a Masterpiece? What is a Masterpiece? What is a Masterpiece? is a 1979 non-fiction book by British historian Kenneth Clark. It is a transcribed version of the Walter Neurath memorial lectures given by Clark. The work, initially released on 1 January 1979, received a Thames & Hudson republication on 1 May 1992. Kenneth Clark had already achieved fame with a series of popular books while also serving as, from 1969 on, the writer, producer and presenter of the BBC programme, "Civilisation", a pioneering television documentary series. The prestigious series earned a Peabody Award as well as general commercial success. In the work,