I’m pleased to be giving away this book.Of all the books I read on the Hollow Earth, this one by Marshall Gardner in 1923 was one I used a lot. To me, this was the best of all the old books written on the subject. I was so impressed with this old book that my goal was to write a new book that could finally take its place, and that resulted in my book Hollow Planets.

You can download Marshall Gardner’s book here: 02_A_Journey_to_the_Earth-Marschall_B.Gardner