Samuel Birley Rowbotham (1816–1884) was an English inventor and writer who wrote Zetetic Astronomy: Earth Not a Globe under the pseudonym "Parallax". His work was based on his decade-long studies of the Earth and was originally published as a 16-page pamphlet (1849), which he later expanded into a 430-page book (1881). According to Rowbotham's method, which he called Zetetic Astronomy, the Earth is an enclosed plane, centered at the North Pole and bounded along its outward edge by a wall of ice, with the Sun, Moon, planets, and stars only several hundred miles above the surface of the Earth.
Rowbotham started out as an organiser of an Owenite commune in The Fens, where he formulated his theories about the Earth. After measuring a lack of curvature on the long straight drainage ditches of the Bedford Levels in his first Bedford Level experiment, he was convinced of the flatness of the Earth and began to lecture on the topic. He took a little time to learn his trade, running away from a lecture in Blackburn when he couldn't explain why the hulls of ships disappeared before their masts when sailing out to sea. However, as he persisted in filling halls by charging sixpence a lecture, his quick-wittedness and debating skills were honed so much that he could "counter every argument with ingenuity, wit and consummate skill".
When finally pinned down to a challenge in Plymouth in 1864 by allegations that he wouldn't agree to a test, Parallax appeared on Plymouth Hoe at the appointed time, witnessed by Richard A. Proctor, a writer on astronomy, and proceeded to the beach where a telescope had been set up. His opponents had claimed that only the lantern of the Eddystone Lighthouse, some 14 miles out to sea, would be visible. In fact, only half the lantern was visible, yet Rowbotham claimed his opponents were wrong and that it proved the Earth was indeed flat so that many Plymouth folk left the Hoe agreeing that "some of the most important conclusions of modern astronomy had been seriously invalidated".
In 1861, Rowbotham married for a second time (to the 16-year-old daughter of his laundress) and settled in London, producing 14 children, of whom four survived. He was also alleged to be using the name "Dr. Samuel Birley", living in a beautiful 12-roomed house, selling the secrets for prolonging human life and curing every disease imaginable. Augustus De Morgan refers to him as S. Goulden. He patented a number of inventions, including a "life-preserving cylindrical railway carriage".
His book Zetetic Astronomy - The Earth not a Globe appeared in 1864. His lectures continued and concerned citizens addressed letters to the Astronomer Royal seeking rebuttals for his claims. A correspondent to the Leeds Times observed that "One thing he did demonstrate was that scientific dabblers unused to platform advocacy are unable to cope with a man, a charlatan if you will (but clever and thoroughly up in his theory), thoroughly alive to the weakness of his opponents".
One of Rowbotham's followers, John Hampden, a Christian polemicist, gained notoriety by engaging in raucous public debates with leading scientists of the day. A bet involving the prominent naturalist Alfred Russel Wallace in the famous Bedford Level experiment led to several lawsuits for fraud and libel and Hampden's imprisonment.
After Rowbotham's death, Lady Elizabeth Blount founded the Universal Zetetic Society, which attracted thousands of followers, published a magazine entitled The Earth Not a Globe Review and remained active well into the early part of the 20th century. After World War I, the movement underwent a slow decline, but it was revived in 1956 as The Flat Earth Society.
In the United States, Rowbotham's ideas were taken up by the Christian Catholic Apostolic Church and promoted widely on their radio station. His work in the United States was continued by William Carpenter. Carpenter, a printer originally from Greenwich, England, a supporter of Rowbotham and published Theoretical Astronomy Examined and Exposed — Proving the Earth not a Globe in eight parts from 1864 under the name Common Sense. He later emigrated to Baltimore where he published A hundred proofs the Earth is not a Globe in 1885. He argues that:
- "There are rivers that flow for hundreds of miles towards the level of the sea without falling more than a few feet — notably, the Nile, which, in a thousand miles, falls but a foot. A level expanse of this extent is quite incompatible with the idea of the Earth's convexity. It is, therefore, a reasonable proof that Earth is not a globe."
- "If the Earth were a globe, a small model globe would be the very best — because the truest — thing for the navigator to take to sea with him. But such a thing as that is not known: with such a toy as a guide, the mariner would wreck his ship, of a certainty!, This is a proof that Earth is not a globe."