3 related novelets from Amazing (1935-1936) about Professor Jameson - the last Earthman:
Zora of the Zoromes
Space War
Labyrinth

Jameson's tomb was discovered millenia later by the machine men of Zor, who brought him back to life and offered to make him one of them - into a nearly immortal being of metal, wandering throughout the Universe in search of knowledge and adventure! The Zoromes had made one mistake in their scientific history: they had helped another race of beings change over into machine bodies - the Mumes of the world Mumed. The Mumes turned on their benefactors, schemed for greater power, and finally the 2 races of machine-men became the bitterest of enemies.