Letters from Crotch, William Duppa to Charles Lyell, 5 January 1865 - 11 July 1865

Crotch refers to his two visits to the Canary Islands and his plans to write an entomological history of the Island, refers to the works of M. Hastings, and includes photographs of his sketches of ‘the valley of Hermigua’. Lyell has summarised these letters as:
1) Crotch on canaries and old rocks of Hierro.
2) Crotch on Canary Islands This letter refers to the work of M. Hastings, and includes labelled diagrams of large caverns and the movement of water through them. There are 4 photographs of his sketches of the valleys enclosed with details of place names written on the back: Valley of Hermigua, La Gomera looking South; El Rico de Feydi (place name is unclear) from the South West; ‘From our tent’ North Crater Wall La Fortaleya; Valley of Hermigua La Gomera looking North
3) Elevation crater theory receipt of Etna.