Alfred Russel Wallace versus the Kent Hovind of his day

Christine Gardwood's Flat Earth: The History of an Infamous Idea tells the story of how a 19th century British socialist and charlatan going by the name "Parallax" was able to create a movement that believed that true "science" shows that the Earth is flat rather than round, just as the Bible supposedly claims. This despite the belief in a flat Earth having been a dead idea for more or less thousands of years.

One of the more interesting sections of the book recounts Alfred Russel Wallace, the man who co-discovered evolution by natural selection with Charles Darwin, deciding to take up a flat earther on an open bet that he could prove the spherical nature of the Earth. On Wednesday, Jan. 12, 1870, John Hampden had placed the following ad in the new weekly scientific journal Scientific Opinion:

What is to be said of the pretended philosophy of the 19th century, when not one educated man in ten thousand knows the shape of the earth on which he dwells? Why, it must be a huge sham! The under signed is willing to deposit from £50 to £500, on reciprocal terms, and defies all the philosophers, divines and scientific professors in the United Kingdom to prove the rotundity and revolution of the world from Scripture, from reason or from fact. He will acknowledge that he has forfeited his deposity, if his opponent can exhibit, to the satisfaction of any intelligent referee, a convex railway, river, canal, or lake.

I couldn't help but think of Kent Hovind's creationist challenge when I read this. And like Hovind, Hampden had no intention of ever paying up on his challenge, as he had already concluded that his beliefs were correct. Unlike Hovind who never actually got around to coming up with distinct terms for his bet, however, Hampden did end up agreeing to terms of a bet with Wallace.

They both agreed to put up £500 and to conduct a test on the Old Bedford Canal: markers were to be spaced out on the canal and then observed via a telescope, the curvature of the Earth should make the middle marker appear above an observer's line of sight. Wallace and Hampden were to each pick an impartial judge to referee the contest; Wallace picked a judge who was appropriate for the task, but Hampden picked a close flat earth confidant. As Wallace was unaware of their connection, he didn't object to the nomination.

The test was conducted and, as anticipated, demonstrated the curvature of the Earth. Yet Hampden's representative refused to acknowledge as much, claiming that the test had proved the Earth flat. This is despite the pre-agreed upon condition that would have proved the Earth's curvature having been demonstrated!

Wallace was eventually awarded the bet money by the man overseeing the bet, but ended up having to return the money to Hampden later as a judge ruled that since Hampden had demanded his money returned before the bet was paid out he was entitled to have it back. However, this merely offset the money that Hampden owed Wallace, as he had been engaging in a relentless, 15 years long, campaign of libel and defamation against Wallace. At one point he even went so far as to issue Wallace a vague death threat.

Most of this section of the book appears to be available at Google books, starting on page 83. The Alfred Rusel Wallace Page also has several letters that Wallace wrote about the incident:

Letters to the Editor Concerning the Bedford Canal "Flat Earth" Experiment (1870)

Reply to Mr. Hampden's Charges Against Mr. Wallace (1871)

The Hampden-Wallace Libel Case (1875)

In that first link, Wallace patiently, yet with obvious frustration, explains how Hampden's judge William Carpenter was able to convince himself the telescope did not show earth curvature and why he is wrong.