Reprint of the 3rd story from Tales to Astonish #33 (originally printed as The Frightened Man!)
A scientist living during the height of the cold war invents a time machine to escape the fear of the present day by traveling into a past epoch. The first place he lands is the French Revolution. He flees guards who take his clothes for those of an aristocrat and want to behead him. The next place his machine takes him is the Spanish Inquisition (which no one expects). They put him on trial for sorcery, so he jumps into his machine and lands in the time of the Black Plague. He thinks maybe one more time will deposit him in a less fearful age, but he ends up in gladiatorial Rome. He resolves to return to his own century having learned the lesson that every age had its dangers and mankind survives by facing up to them.