At the Earth’s Core (1914)

All-Story Weekly - April 4, 1914 thumbnail
All-Story Cavalier Weekly - May 1, 1915 thumbnail
All-Story Weekly - April 4, 1914
All-Story Cavalier Weekly - May 1, 1915

The first appearance of Burroughs’ Pellucidar. This story wasn’t printed as a hardcover until 1922. It looks like this artwork was cropped and reused when the sequel was published the next year.

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Hell Below

Doc Savage 1943 September

Doc Savage Mixes Things With An Old Indian Fighter, A Scatter-Brained Heiress, And A Couple Of Nazi Submarines

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