Sir Archibald Geikie corresponded with a large number of people both socially and in the course of his work. This sub-series is alphabetically arranged and includes a variety of correspondents. The majority of correspondence concerns minor matters of professional interaction such as requests or thanks for copies of geological papers. These include letters from the photographer Tempest Anderson, a fellow geologist Samuel Allport and the American naturalist Alexander Agassiz. 6 of the letters from the father of the geologist William Anderson, are of a social nature, mostly concerning news of his son's career.