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From Leonard Darwin   [29 March 1872]1

Dear Father

The following is the solid content of the box, which I forgot to measure last week.

211.44 Cubic inches

Your affec son. | Leonard Darwin

Iron box of earth.

Measurement after being well dried before the fire. = 180.8 Cubic inches. This shews that it has diminished 10 per cent on the original earth, without taking into account internal shrinking, although cracks were visible on the surface.2

CD note:

March. 29.1872.

Leonard

Earth dug out of ground & thrown up in fortification   increase ⁠⟨⁠of⁠⟩⁠ above 112th of bulk.—3

Footnotes

1
The date is established by CD’s note.
2
In Earthworms, pp. 161–2, where he gave measurements of dried earth by weight rather than volume, CD concluded that the largest castings were produced on the poorest soils, indicating that worms had to swallow a greater amount of earth on poor land in order to obtain enough food.
3
A further set of calculations, made by George Howard Darwin on the letter, estimates that the loss in volume of the dried earth is approximately 116.

Bibliography

Earthworms: The formation of vegetable mould through the action of worms: with observations on their habits. By Charles Darwin. London: John Murray. 1881.

Summary

Data relating to experiments; shrinkage of earth on drying.

Letter details

Letter no.
DCP-LETT-8260
From
Leonard Darwin
To
Charles Robert Darwin
Sent from
unstated
Source of text
DAR 162: 75
Physical description
ALS 2pp damaged †, † (by G.H. Darwin)

Please cite as

Darwin Correspondence Project, “Letter no. 8260,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-8260.xml

Also published in The Correspondence of Charles Darwin, vol. 20

letter

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