Croll, James, 1821-1890 (physical geologist and Keeper of Maps and Correspondence, Geological Survey of Scotland)

Scope and Contents Letter to Sir Charles Lyell from James Croll regarding another alteration to his Submergence Theory which he explains in sheets which he encloses for Lyell to send to The Reader with his earlier letter (See Lyell 1/593-594). His alterations concern the structure of ice caps which have a solid crust covering and a liquid nucleus, 8 January 1866.

Scope and Contents Letter to Sir Charles Lyell from James Croll concerning the effect of ice-caps upon the level of the ocean and announcing the publication of an important paper by Rev. G Fisher on the subject, 8 February 1866.

Scope and Contents Letter to Sir Charles Lyell from James Croll concerning the extent to which the centre of gravity of the earth would be displaced by ice caps 2000 feet and 3000 feet thick, 16 February 1866.

Scope and Contents Letter to Sir Charles Lyell from James Croll concerning calculations of Charles Moore's which Lyell had sent to him and discussing his own calculations which show how much the centre of gravity of the Earth would have been displaced by the weight of ice-caps, 17 February 1866.

Scope and Contents Letter to Sir Charles Lyell from James Croll concerning the calculations made by himself and Charles Moore as to the shift in the centre of gravity due to ice-caps and concerning Solstitial points and Perihelion in the earth's orbit, 28 February 1866.