Asks ACR to establish height of Moel Tryfan in Caernarvonshire; "in my notice on this hill [""Ancient glaciers of Caernarvonshire"" (1842), Collected papers 1: 163–71] I give a very much less height than others". [See also another mention of the elevation of Moel Tryfan in "On the transportal of erratic boulders" (1848), Collected papers 1: 218–27.]
Down Farnborough Kent
Would you be so kind as to inform me, as you will probably know, or perhaps would be so
good as to look at the Ordnance Maps, what is the height of Moel Tryfan in
Carenarvonshire situated in a line nearly between Snowdon & Caernarvon. This hill has been repeatedly mentioned, since M
Yours sincerely | C. Darwin
- f1 1168.f1CD sought this information for use in his paper, ‘On the transportal of erratic boulders’, read on 19 April 1848 (Collected papers 1: 218–27).
- f2 1168.f2Joshua Trimmer discovered broken fragments of marine shells in diluvial sand and gravel ‘1000 ft above the level of the sea on the summit of Moel Tryfan’ (Trimmer 1831, p. 331). Referring to Trimmer's discovery, CD stated that the beds which included the shells were undoubtedly ‘deposited in the ordinary manner under the sea’ (Collected papers 1: 223).
- f3 1168.f3Trimmer had originally given the height as 1000 ft (see n. 2, above). In ‘Notes on the effects produced by the ancient glaciers of Caernarvonshire’ (Collected papers 1: 167), CD gave the height as 1192 ft, but he cited as his source Murchison 1839, 2: 528, where the height is given as 1692 ft. In ‘On the transportal of erratic boulders’, the height is recorded as 1392 ft (Collected papers 1: 219).