It was Sir Edmund Halley's ideas which lead to the concept of gigantic Polar Holes. Eventually much of Hollow Earth theory was to revolve around this single idea. Polar Holes were seen as the single definitive proof that the planet may or may not be hollow.

Gardner and Reed tried earlier this century to prove that a gigantic hole existed beyond latitude 80 degrees North. They believed that from 80 degrees North the Earth began curving inwards and that various polar explorers had begun wandering into a giant hole. While a great deal of their evidence is vague, some of it is nevertheless interesting. They tried to prove for example that the Arctic was in fact much hotter than scientists had predicted. This, so they said, was because there was a tropical climate inside a Hollow Earth and warm winds sometimes blew from the North from inside a Polar Hole. They saw any warm winds coming from the North as being an indication of a Polar Hole. They also turned to animal behaviour, citing examples of animals seen moving north for winter instead of south. Gardner made much of the millions of birds on Spitzbergen which is very close to the North Pole. He believed large numbers of birds and fish emanated from inside the Earth. He pointed to the vast numbers of whales and fish which existed in the Arctic and how their numbers dwindled as one moved closer to the equator. He believed that enormous shoals of fish and whales emanated from an Inner Earth which was over-flowing with life.

Gardner also attacked the navigational methods of the polar explorers. He tried to show that arctic navigation was vague and untrustworthy. He did his best to demonstrate that they were lost much of the time and were merely wandering around or in a Polar Hole. When Peary reached the North Pole he attacked Peary by saying that Peary could not have travelled as fast as he said he did. I was rather stunned that Gardner did not do the obvious thing and try to use Peary's sledding speeds as an indication that Peary might be going over the rim of a Polar Hole and down into the Inner Earth. The controversy over Peary's sledding speeds (which remains to this day) has to do with the fact that he actually travelled faster and faster as he went north. In this chapter I analyse Peary's sledding speeds to see if one can resolve the problem. My conclusion? There are many valid reasons why Peary's teams speeded up. In fact, I can find nothing abnormal about Peary's sledding speeds - even though these are still debated among Arctic experts to this day!

I also look into the issues of navigation on a Hollow Planet. How would navigation really work if you're near a Polar Hole?

Marshall Gardner's 1920's book was the last serious attempt at proving that planets might be hollow. The subject then died down until the 1960's. In the 1960's a number of people looked at NASA space photographs to see if Polar Holes could be seen. Various books were published showing these photos and claiming a NASA cover-up. I conducted a search for Polar Hole photographs. Many people on my Hollow Planets E-Mail List joined in and we scoured the Internet and any other sources we could find. We found a number of very interesting photographs of the Earth, and some were very fascinating.

Look at the strange circle at the top of the photograph below. Pretty interesting huh? (Click on the image for a close-up view). And it lies on the edge of the polar ice cap - not far from where one would expect to find a Polar Hole. Well, its no Polar Hole. Some calculations showed that it lay near the Aleutian islands and is a weather phenomenon known as the Aleutian Low.

A friend of mine, Remi Du Bois, even went to NASA's Goddard Space Flight Centre to look through various old photographs and chat to the scientist who had them in his archive. Eventually I had a collection of more than 30 strange photographs which are analysed in this chapter. After looking through all these photographs and all this evidence I was forced to conclude that gigantic Polar Holes of 1,400 - 2,000 miles in diameter could not possibly exist here on Earth and that none of these photographs actually show anything like a Polar Hole at all.

However, what of a small Polar Hole? Could something like that still remain hidden in the Arctic?