These letters are to William Hepworth Dixon, who was editor of the "Athenaeum," a journal of literature, science, the fine arts, music, and drama, from 1871 to 1900. They concern current publications and publishing expenses, Michael Faraday, astronomy, perspective, M. F. Maury, P. B. Du Chaillu, all in relation to the "Athenaeum" or letters to the editor thereof.

Series I is a miscellaneous collection of letters concerning geology, geological exploration of Russia, entomology, glaciers, appointments in the British Museum, Geological Society of London business, Royal Geographical Society, references to David Livingstone, and zoology. Series II consists of letters written from America, to Murchison, discussing geology, natural history, and contemporary topics.

A miscellaneous collection of letters, mainly of English scientists, written to various people. There are mostly one or two letters, except for those of John Peter Gassiot, William Huggins, Edwin R. Lankester, James Mackintosh, David Prain, and William Whewell.

These are letters to Quetelet primarily on the subject of astronomy (meteorological observations), including charts showing directions of shooting stars.