James Croll

James Croll ( born January 2, 1821 in Cargill, † December 15, 1890 in Perth ) was a Scottish naturalist.

Life and work

James Croll grew up in the province in poverty. His education he acquired as an autodidact, he was an avid reader of physical and astronomical books. An apprenticeship as a wheelwright he gave up for health reasons and worked in various jobs, including as a carpenter, an insurance salesman, waiter and tea merchant. In 1848 he married Isabella MacDonald. In 1859 he got a job as a janitor at the Museum of Anderson University in Glasgow, Scotland. This gave him access to scientific literature. After he had brought his brother to take over the porter activity, he started in the library subjects such as physics, mechanics, astronomy, hydrostatics, study and published papers on the movements of the earth.

Since 1864 he corresponded with Sir Charles Lyell on his idea that a correlation exists between the occurrence of ice ages and changes in the Earth's orbit. Its publication in 1864 in the Philosophical Magazine on the subject has been recognized as a work of the highest quality. Croll then got a job at the Geological Survey of Scotland, where he served from 1867 to 1881. There you furthered his research and he has published books and articles in professional journals. Charles Darwin later used his ideas.

The work on the relationship between the ice age and the Earth's orbit was ahead of his time. He expressed was the first to conjecture, cyclical changes in the Earth's orbit from an ellipse ( slightly oval ) to a nearly circular orbit and back again could be the explanation for the beginning and end of the ice ages represent. Today Croll's theses under the term Milankovitch cycles are known, which are named after a 1879 Serb -born scientists.

He was appointed in 1876 as a member of the British Royal Society. The University of St Andrews awarded him an honorary doctorate. In 1880, he retired into private life.


  • The Philosophy of Theism ( 1857)
  • Climate and Time, in Their Geological Relations (1875 )
  • The Philosophic Basis of Evolution ( 1890)