Circle of a sphere the Equator the only great circle. By contrast, all meridians of longitude, paired with their opposite meridian in the other hemisphere, form great circles. The diameter of the sphere which passes through the center of the circle is called its axis and the endpoints of this diameter are called its poles. A circle of a sphere can also be defined as the set of points at a given angular distance from a given pole. When the intersection of a sphere and a plane is not empty or a single point, it is a circle. This can be seen as follows:
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,