From L. C. Wedgwood [8 February 1872]1
Leith Hill Place, | Dorking.
Xperimt. 1. Measurement of depth of furrows at top and bottom of slope— Old ploughed land has been pasture at least 24 years. Field sloping in 2 directions, but much most along furrows. Measured by laying a straight rod across from ridge to ridge, and measuring distance from furrow to rod.2
Furrow No 1:— (Jan 15th 1872)
Top. (before there is much slope) 4 in
middle of slope—————3
Bottom of slope (on flat) 3
Furrow No 2:—
Top (nearly flat) about 3
near top of slope " 4
Middle " 3
Bottom " 4
Furrow No 3:—
Top.— about 3
Nr. top of slope " 3
Bottom nearly 3
Furrow No 4:—
Top abt. 4
Top of slope " 3
Bottom " 3
It was impossible in above experiment to obtain very accurate results,— any little irregularities in the surface making all the difference. There were marks of draining-pipes running across furrows nr. top & bottom
Experimt. 2— Trenches dug one on ridge, one in trough of furrow side by side in same field on slope. Jan. 11th. Line of worm-mould very ill-defined— No apparent difference
Beginning of Feb. Two more trenches dug in same field on nearly flat ground along line of furrow.
Worm-line very ill-defined only to be seen by an occasional bit of charcoal. These are very rare, but form a sufficiently straight line I think to preclude chance
No 1. (ridge) worm-mould 2–4 inches
No 2 (furrow) — — 3–5 "
Experimt. 3. A sod dug out near top of steep slope in garden and at bottom. (Feb 6th.)
Top worm-mould 4 inches
Expt. 4 Worm mould on common near sqre. yard 3–4 in.
On terrace near sq yd. 33
Describes earthworm experiments. She has measured depth of mould in various locales, e.g., on ridges and furrows of an old ploughed field.
Please cite as
Darwin Correspondence Project, “Letter no. 8203,” accessed on 24 April 2017, http://www.darwinproject.ac.uk/DCP-LETT-8203