Samuel Birley Rowbotham
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.
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.[6] 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."--Wiki
Pictured below is a drawing of one of his experiments to prove a flat earh
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In this video beginning from "51:51 to 57:57" is a presentation of his work.
You go right to this section of the video and and only view 6 min and see what is the origin of the modern flat earth movement.
--Dave