Charles Petzold

When did the world get to be so old? In Newton's time, the world was assumed to be about six thousand years old, but by the time of Darwin's Origin of Species, it had become millions and billions of years old. When did this happen?

That was a question I felt I needed to answer for my book-in-progress Computer of the Tides: Lord Kelvin’s Machine to Disprove Evolution.

Following the 1859 publication of Origin of Species, William Thomson (Lord Kelvin) became interested in various ways to calculate the age of the earth through principles of physics. He got interested in the tides partially because he thought they could help him show that the earth was not old enough for evolution to occur. For my book, I needed to put that controversy in context with the earlier age-of-the-earth controversy that overturned the six-thousand-year chronology. In the current chapter outline for Computer of the Tides, this history is Chapter 4.

In a couple of the many books I consulted, I encountered 4½ lines of verse from a 1785 poem by the English evangelical poet William Cowper (pronounced "cooper") that seemed to express a prescient panic that recent developments in explorations of the earth contradicted the Genesis chronology. Here are those lines:

        Some drill and bore
The solid earth, and from the strata there
Extract a register, by which we learn,
That he who made it, and revealed its date
To Moses, was mistaken in its age.

Of course, Cowper is writing with wry irony about God misinforming Moses about the age of the earth.

At first, 1785 seemed a little early for this much concern. I wondered: How did William Cowper come to write this verse? What did he learn that made him so nervous? I thought that if I discovered the basis of his anxiety, I could use that as a "hook" for the chapter.

After much research into William Cowper and his reading material, I pretty much figured out that Cowper learned about people drilling and boring through strata from book reviews in his favorite magazine, the London-based Monthly Review. But when I started putting it all together, it was way too long for the chapter. The chapter must extend well into the 19th century with James Hutton and Georges Cuvier and William Buckland and Charles Lyell and the Bridgewater Treatises and Hugh Miller and Philip Henry Gosse right up to Alfred Russel Wallace, and I simply could not use up half the chapter's page count with an analysis of the background of a 1785 poem.

So except for a brief mention, I pulled William Cowper from Chapter 4. But I just couldn't let all that good research go to waste, so the material is now an independent essay called William Cowper and the Age of the Earth.