Frank Rudolph Paul (1884 – 1963) was an illustrator of US science fiction pulp magazines in the field. He was influential in defining what both cover art and interior illustrations in the nascent science fiction pulps of the 1920s looked like.
He was very innovative in the depiction of spaceships. Several of his illustrations were disc shaped and it has been speculated that he may have, accidentally, created the UFO craze when the first sighting of lights in the sky were described as disc shaped.
This is awesome! My favorite is Neptune. Frank Rudolph Paul captured the true spirit of, well, his pictures say it all. Thanks for sharing these.