Letter to Marshall B. Gardner (31 january 1914)
In 1913, Marshall B. Gardner privately published Journey to the Earth's Interior in which he rejected the notion of concentric spheres but swore that inside the hollow earth was a sun 600 miles in diameter. He also claimed that there were huge holes a thousand mile wide at the poles leading to this interior world.
The Conan Doyle letter was published in the 1920 reprint of Gardner's book, in chapter 25 : "How our theory has been received".
I read your little book (and big theory) with great interest. It is so very original and actually explains so many facts, that if it were not that both poles had actually been attained, I should be a convert. But I must thank you none the less for a most interesting exposition.
Arthur Conan Doyle
- Source: Brian Pugh Collection.