Dr. Alfred Harker, F.R.S

Abstract

ON February 19, Dr. Alfred Harker, emeritus reader in petrology in the University of Cambridge, attains his eightieth birthday, and petrologists throughout the world will join in offering their congratulations. Graduating from St. John's College in mathematics in 1882, he had already come into contact with Prof. McKenny Hughes, and was shortly appointed to the staff of the Woodwardian Museum. His earliest original work dealt with the development of cleavage in slates; but he soon turned to petrographic work on the igneous rocks of North Wales, with a series of publications culminating in the Sedgwick prize essay on “The Bala Volcanic Series”. In the Lake District, he began (with J. E. Marr) a study of the Shap granite and its aureole, and later of Carrock Fell. During this period also appeared the first edition of “Petrology for Students”, now in its seventh edition. From 1895, Harker was for ten years attached to the Scottish branch of the Geological Survey of Great Britain, and worked in Skye and the Small Islands of Inverness-shire, collaborating in the production of the official maps and memoirs, and writing a special memoir on “The Tertiary Igneous Rocks of Skye”. Much of this work was necessarily descriptive, and the genetic considerations to which it gave rise were brought together in “The Natural History of Igneous Rocks”, a pioneer work on petrology in its treatment of rock-magmas as complex solutions. As president of the Geological Society, he expanded further ha his address in 1917 the significance of igneous activity as an integral part of the historical geology of Britain. The central themes of his address the following year, that metamorphism is to be conceived as a progressive change, and that Great Britain offers unique opportunities to investigate such changes, find fuller expression in his book, “Metamorphism”, published in 1932. Since his retirement, Dr. Harker has remained actively associated with the petrological collections at Cambridge, where the Harker collection qf rock-slides now numbers forty thousand sections. He was awarded the Wollaston Medal of the Geological Society of London in 1922 and a Royal Jtfedal of the Royal Society in 1935.