"Teed expounded on his notions in a [ book ] 'The Cellular Cosmogony, or, the Earth a Concave Sphere', writing under the pseudonym of Koresh, the Hebrew name for Cyrus. He explained that the [ known world ] is on the concave, inner surface of a sphere, outside of which there is only a void. At the centre of the sphere, the rotating sun, half dark and half-light, gives an illusion of rising and setting.

The moon is a reflection of the earth's surface; the stars and planets reflect from metallic planes on the earth's concave surface. The vast internal cavity is filled with a dense atmosphere that makes it impossible to see across the globe to the lands and peoples on other sides.

Odd as it was, his theory could not be disproved mathematically. Indeed, Teed offered a $10,000 reward to anyone who could disprove his theory, but no one took him up."

http://mystical-locations.info/hollow_earth_teed.html