From:
Charles Robert Darwin
To:
Lucy Caroline Wedgwood; Lucy Caroline Harrison
Date:
5 Jan [1872]
Source of text:
Cambridge University Library (Add 4251: 331)
Summary:
Asks her to probe worm-holes on grassy slopes with a knitting needle to ascertain whether they come out at right angles to the slope or to the horizon.
Contributor:
Darwin Correspondence Project
