In 1818, Army veteran John Cleves Symmes Jr. declared that the earth was hollow and proposed to lead an expedition to its interior. He promoted the theory in lectures and even won support on Capitol Hill. In this week's episode of the Futility Closet podcast we'll describe Symmes' strange project and its surprising consequences. We'll also revisit age fraud in sports and puzzle over a curious customer. Intro: Grazing cattle align their bodies with magnetic north. The Conrad Cantzen Shoe Fund buys footwear for actors. Sources for our feature on John Cleves Symmes Jr.: David Standish, Hollow Earth: The Long and Curious History of Imagining Strange Lands, Fantastical Creatures, Advanced Civilizations, and Marvelous Machines Below the Earth's Surface, 2007. Peter Fitting, ed., Subterranean Worlds: A Critical Anthology, 2004. Martin Gardner, Fads and Fallacies in the Name of Science, 1986. Paul Collins, Banvard's Folly: Thirteen Tales of Renowned Obscurity, Famous Anonymity, and Rotten Luck, 2015. Americus Symmes, The Symmes Theory of Concentric Spheres: Demonstrating That the Earth Is Hollow, Habitable Within, and Widely Open About the Poles, 1878. James McBride and John Cleves Symmes, Symmes's Theory of Concentric Spheres: Demonstrating That the Earth Is Hollow, Habitable Within, and Widely Open About the Poles, 1826. Adam Seaborn, Symzonia: A Voyage of Discovery, 1820. Donald Prothero, "The Hollow Earth," Skeptic 25:3 (2020), 18-23, 64. Elizabeth Hope Chang, "Hollow Earth Fiction and Environmental Form in the Late Nineteenth Century," Nineteenth-Century Contexts 38:5 (2016), 387-397. Marissa Fessenden, "John Quincy Adams Once Approved an Expedition to the Center of the Earth," smithsonianmag.com, May 7, 2015. Daniel Loxton, "Journey Inside the Fantastical Hollow Earth: Part One," Skeptic 20:1 (2015), 65-73. "Journey Inside the Fantastical Hollow Earth: Part Two," Skeptic 20:2 (2015), 65-73. Matt Simon, "Fantastically Wrong: The Real-Life Journey to the Center of the Earth That Almost Was," Wired, Oct. 29, 2014. Kirsten Møllegaard and Robin K. Belcher, "Death, Madness, and the Hero's Journey: Edgar Allan Poe's Antarctic Adventures," International Journal of Arts & Sciences 6:1 (2013) 413-427. Michael E. Bakich, "10 Crazy Ideas From Astronomy's Past," Astronomy 38:8 (August 2010), 32-35. Darryl Jones, "Ultima Thule: Arthur Gordon Pym, the Polar Imaginary, and the Hollow Earth," Edgar Allan Poe Review 11:1 (Spring 2010), 51-69. Johan Wijkmark, "Poe's Pym and the Discourse of Antarctic Exploration," Edgar Allan Poe Review 10:3 (Winter 2009), 84-116. Donald Simanek, "The Shape of the Earth -- Flat or Hollow?" Skeptic 13:4 (2008), 68-71, 80. Duane A. Griffin, "Hollow and Habitable Within: Symmes's Theory of Earth's Internal Structure and Polar Geography," Physical Geography 25:5 (2004), 382-397. Tim Harris, "Where All the Geese and Salmon Go," The Age, July 22, 2002. Victoria Nelson, "Symmes Hole, or the South Polar Romance," Raritan 17:2 (Fall 1997), 136-166. Hans-Joachim Lang and Benjamin Lease, "The Authorship of Symzonia: The Case for Nathaniel Ames," New England Quarterly 48:2 (June 1975), 241-252. Conway Zirkle, "The Theory of Concentric Spheres: Edmund Halley, Cotton Mather, & John Cleves Symmes," Isis 37:3/4 (July 1947), 155-159. William Marion Miller, "The Theory of Concentric Spheres," Isis 33:4 (December 1941), 507-514. "John Cleves Symmes, the Theorist: Second Paper," Southern Bivouac 2:10 (March 1887), 621-631. Will Storr, "Journey to the Centre of the Earth," Sunday Telegraph, July 13, 2014. Richard Foot, "Believers Look for Fog-Shrouded Gate to Inner Earth," Vancouver Sun, May 30, 2007. Umberto Eco, "Outlandish Theories: Kings of the (Hollow) World," New York Times, July 21, 2006. Mark Pilkington, "Far Out: Going Underground," Guardian, June 16, 2005. Leigh Allan, "Theory Had Holes In It, Layers, Too," Dayton Daily News, Dec. 11, 2001. Tom Tiede, "John Symmes: Earth Is Hollow," [Bowling Green, Ky.] Park City Daily N