Letters from Trimmer, Joshua to Charles Lyell, 28 December 1839 - 26 June 1857

Lyell summarises the letters as:
1) 'Mr Trimmer on Moel Tryfan shells being all recent species'
2) 'Trimmer on glacial evidence and on hail marks'
3) 'Trimmer on drifts'
4) 'Trimmer on superficial gravel soils etc'
5) 'Trimmer on draining by following the subsoil natural grooves'. Also includes two newspaper clippings
6) 'Post glacial deposits of Thames Valley, June 10th 1857'. Printed Advertisement for the Keythorpe System of Land Drainage.
7) 'Relative age of glacial & Cromer to Selsea' [sic Selsey], June 18 1857'. Lyell also makes notes on this letter.
8) 'Trimmer on Erith & Grays beds post-glacial? Origin of his 'warp drift'.