RECORD: Darwin, C. R. 1857.03.29. With respect to cliff of 500 ft wearing 1 inch in century it is same to say that cliff 1 yard high wears back. CUL-DAR205.9.328. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 10.2021. RN1
NOTE: The brown crayon number '22' indicates that this document was filed by Darwin in his portfolio for the subject of Palaeontology: extinction.
Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR205.9 contains notes on palaeontology and geology [regarding theory of evolution].
[328]
22
March 29 /57/
With respect to cliff of 500 ft wearing 1 inch in century it is same to say that cliff 1 yard high wears back
[calculations] nearly 14 yard in century; ie 1 yard in little more than 7 years
One yard in very little more than 7 years.
Mem. Whilst under sea no wear - very little when upraised. If we give to Wealden 300, we may really twice or thrice or more long - Mem in many parts cliffs are deserted - Now take one of lower Eocene Mollusca which has descendants, then will have been if annually given 600 million generations
Suppose it to change slowly - what a series - What chance of completing such a series.
[in margin:] Not quite same fallen wd be eaten from by wear
[328v]
[calculations]
Land during every Tertiary periods
Take level by chance - if too low or too high no action, -The 300 million must be multiplied many times
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 25 September, 2022