# From Amy Ruck to Horace Darwin   [1 February 1872]1

Will you tell Mr. Darwin that in the case in which the furrows run down the hill & are 4in at the top & 1in at the bottom—the slope is 15o and faces North East. The furrows are about 7 ft apart & on the level ground above are 4in 3$\frac{1}{2}$in deep, although it is difficult to measure these on account of the mole hills—40 paces long.

On another slope of 15o facing S. West the furrows were scarcely perceptible but on level ground at the bottom the same furrows were 3$\frac{1}{4}$ 2$\frac{1}{2}$in deep. The length of the slope was 80 paces— On another short slope of 10o the furrows at the top were 3$\frac{1}{2}$ at the bottom 1$\frac{1}{4}$ 1$\frac{1}{2}$in deep.2

## CD annotations

Top of letter: ‘Feb 1. 1872 (2d note)’
Bottom of letter: ‘Amy Ruck’

## Footnotes

The date is established by CD’s annotation.
The measurements were made for CD’s research on the action of worms in turning over soil (see also letter from Amy Ruck to Horace Darwin, [20 January 1872]). CD wanted to ascertain how long the ridges of ploughed land would persist after the land was last ploughed (see Earthworms, p. 292).

## Summary

Observations on earthworm activity in old furrows on a hillside.

## Letter details

Letter no.
DCP-LETT-8193
From
Darwin, Amy Richenda
To
Horace Darwin
Sent from
unstated
Source of text
DAR 176: 222
Physical description
†(by CD)