Early Believers
Edmund Halley in 1692 (Philosophical Transactions of Royal Society) puts
forth idea of Earth being hollow with 2 hollow shells and a solid sphere
nested inside. This was done to explain anomalous magnetic compass
readings. Said atmosphere inside was luminous (and possibly inhabited) and
escaping gas the cause of Aurora Borealis.
Leonard Euler got rid of multiple shells and had an interior sun - to
provide light to advanced inner-earth civilization.
Sir John Leslie would place 2 suns in hollow earth- named Pluto &
Proserpine.
These ideas (apparently Halley's') influenced Cotton Mather, who placed the
ideas in chapter 24 (on Magnetism) of his book Christian Philosopher.
Also, Leslie was inspiration for Verne's Voyage to the Center of the
Earth.