GSL/L/R/1/70
Letter from James HALL
25 May 1834
GSL/L/R/11/8
Letter from Charles LYELL
1 Jan 1849
LDGSL/838/H/5
Murchison correspondence: letter from James HALL
29 Jan 1847
LDGSL/838/L/17/25
Murchison correspondence: letter from Charles LYELL
14 Nov 1841
LDGSL/947/6/T/3
Geological colouring on Lay's 'Map of the United States...'
1834