Petrography rock was affixed to a microscope slide and then ground so thin that light could be transmitted through mineral grains that otherwise appeared opaque. The position of adjoining grains was not disturbed, thus permitting analysis of rock texture. Thin section petrography became the standard method of rock study. Since textural details contribute greatly to knowledge of the sequence of crystallization of the various mineral constituents in a rock, petrography progressed into petrogenesis and ultimately into petrology. It was in Europe, principally in Germany, that petrography advanced in the last half of the nineteenth century. The macroscopic characters of rocks, those
What Is History? What Is History? What Is History? is a study that was written by the English historian E. H. Carr. It was first published by Cambridge University Press in 1961. It discusses history, facts, the bias of historians, science, morality, individuals and society, and moral judgements in history. The book was originally part of a series of G. M. Trevelyan lectures given by Carr in 1961 at the University of Cambridge. The lectures were intended as a broad introduction into the subject of the theory of history. Some of Carr's ideas are contentious, particularly his alleged relativism and his rejection of