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Date: 1831
Format: Drawn in the back of a 1830-31 field notebook
Description: The meaning of the cartoon is not clear. Rudwick (1975) suggests that De la Beche is continuing to make fun of Lyell's timescales.
In the geology of the day, loose sediments on the Earth's surface were termed "alluvium" and "diluvium". Alluvium were the most recent sediments, laid down by "ordinary" causes (i.e., observable causes, still in operation today. It is conceptually equivalent to "holocene deposits"). Diluvium were loose sediments which seemed out of place and were not explainable by present processes. They were attributed to the action of massive floods (potentially, but not necessarily, the Great Flood - hence the name). We would now largely consider these to be glacial deposits.
Contrary to modern misconception, most practicing geologists of the day accepted an ancient Earth. There were few scriptural geologists among the leaders of the field. However, Lyell's theories required time far beyond what other geologists were necessarily willing to accept. One of the complaints against his theory is that it never seemed to matter how long something might take, there would always be time enough for it under Lyell's system. (De la Beche explicitly makes fun of this in "Cause and Effect".)
In the sketch "Balance of Power", drawn before "Diluvium and Alluvium", Father Time has a clock measuring time in "millions of centuries" (hundreds of millions of years). If Father Time represents the same timescale here for as "Alluvium", then the alluvial deposits that ought to really take just a few thousand years to form are being represented by millions, or hundreds of millions, of years. If Alluvium is so old, then Diluvium must be immeasurably older. Rudwick thinks the visual style of Diluvium may reference the Ancient of Days (i.e. God) in William Blake's Illustrations of the Book of Job [harvardartmuseums.org].
Clary (2003) has a different interpretation. She notes that De la Beche had himself lately grown wary of "diluvium" as a catagory of sediment. He did not like it. So why would he defend "Diluvium" in this cartoon? Alluvium is seen attacking Diluvium, and geologists that stand on Diluvium are therefore seen as hammering away at it, chipping away at the theory. (Rudwick also notes the geologists on Diluvium, but thinks perhaps they are there because the concept of geologists crawling on something as old as the Ancient of Days might seem comically sacrilegious)
Neither Clary nor Rudwick note it, but there appears to be a figure in Alluvium's pocket. If this is Lyell, like the figures in the previous cartoons, perhaps Lyell is directing Alluvium's activity. Alluvium also wears the glasses of theory. Perhaps Alluvium, controlled by Lyell, is inappropriately encroaching on Diluvium's territory -- after all, Lyell had no space in his theory for catastrophic causes like great floods. All sediment would be alluvial sediment. If this is true, perhaps the geologists are defending the concept of Diluvium?
In the end, this is just a particularly obscure cartoon. Sussing out grand theories of meaning from limited data is exactly the sort of speculation that De la Beche so distrusted.
For more on De la Beche vs Lyell, see this page.
For more on Lyell himself, see his entry on the biography page.
Sources & further discussion:
First described in Rudwick, M. J. (1975). Caricature as a source for the history of science: De la Beche's anti-Lyellian sketches of 1831. Isis, 66(4), 534-560. Link [www.journals.uchicago.edu]
Clary, Renee M. "Uncovering strata: an investigation into the graphic innovations of geologist Henry T. De la Beche." Thesis. (2003). Link [digitalcommons.lsu.edu]
Image yoinked from:
Rudwick (1975)
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