Our goal is to develop an understanding of two topics: the controversies about “fossils/figured stones” and the ideas of Steno.

Harris notes: sections 3 and 4

Section 3 covers the initial growth of science (including Steno) and section 4 the issue of “fossils”. Ancient and medieval naturalist thinking was the background for the 16th-early 18th century debates on fossils (section 4). We will discuss the problems of fossils, ores, denudation and strata with the goal of understanding how different conceptual frameworks influenced interpretations.

Albritton, p. 30-41 and Steno

Albritton’s book is a general survey of geological thought. He has two chapters on Steno – the first one discussed Steno’s interpretation of “tongue stones” as shark teeth based on their form and internal structure. This chapter deals with “The Prodromus” and explains Steno’s work in some detail. It is a useful because Albritton’s description can be read together with the reading selections from Steno’s “Prodromus”. Your may (or should) recall the “three principles” of Steno from prior classes: superposition, lateral continuity, original horizontality. They arose out of his investigations into strata, and provided a basis for developing a strata-based history. These readings will give you a more rounded view into his thoughts on on the origins of strata.

Here are some notes to help you read the “Prodromus” extract and relate it to Albritton’s discussion.

The work was addressed to the Grand Duke of Tuscany, Ferdinand II, Steno’s patron and employer. The two pages set the background for the work. The key point is that merely stating that natural features are poduced by Nature is not a sufficient answer. He argues (taken out of context in middle section on p. 34) that “…the agent, matter and place ought to be taken account of in the production of substances…”

• The first major section discusses the origins of natural objects and the problem of relative ages (bottom of p. 34 to the top of p. 37). The argument starts with general principles and quickly moves to statements about the origin of strata, crystals and fossils (in the restricted sense).
  • What are the general principles?
  • What are his arguments about the origins of strata, crystals and fossils?
• The second section (p. 37-39) concerns strata and includes the principles that we associate with Steno.
  • Steno’s comments on the deposition of strata (p. 37-38) are often overlooked. What is the approach? How could it have been used?
  • How does Steno use his arguments about the relative ages of objects and the water-lain origin of strata?
  • What is the basis for the statements about mountains? Note the “no growing of mountains” – compare this with the ideas from our last discussion.
• The third section concerns crystal forms (p. 40-43) and includes statements about the consistancy of interfacial angles. You do not need to do more than skim over this section.
• The final section (bottom p. 43-44 is Steno’s reconstruction of the history of Tuscany.
  • One remarkable feature of Figure 5 (p. 43): notice the numbering of the figures. The present configuration is first, and subsequent diagramatic reconstructions work backwards in time. What does this suggest about Steno’s thinking? (Until recently many presentations of Steno overlooked this point and some presented the diagrams in the reverse order.

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As before, please come prepared to contribute to a group discussion. Here are some basic questions to consider before class.

• As the knowledge of the natural world developed in the 16th to early 18th centuries, questions around of the origin of ores, landforms and the time scale became important at this time. Base on the short discussions here, what aspects of earlier (Greek to Renaissance) thought shaped the various models presented here?
• Fossils (i.e., anything dug up)
  • What were the key observations in thinking about the origins of fossils?
  • What were the arguments for organic versus inorganic origins?
  • Why was it so difficult to figure out the origin of fossils?
  • What was the relation of fossils to the rest of the natural world?
• Thinking about Steno…
  • What kinds of observations or problems was he addressing?
  • How was the origin of fossils related to strata?
  • How did strata form? Why were some tilted?
  • Beyond geometry, why were Steno’s “principles” important?
  • What processes were involved in his reconstructed history of Tuscany?
  • How does his work compare to other ideas of the late sixteenth-seventeenth centuries?
• Finally, what can we learn about the effort to integrate natural and human history? Why was it important?

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