I've been writing several side stories that will be tucked into the sequel to my book "Copper Knights and Granite Men" that feature Dart. If you're not aware, Dart is a public domain superhero from the 1940s who, while pretty lame in execution, actually has a terribly interesting back story in that he's a Roman Republic era superhero who was turned into a slab of concrete, only to revert to normal circa the 1940s. I thought this played very well with the events of "Copper Knights and Granite Men", which deals with superheroes investigating some museum-goers turned to stone during a robbery, and so I had him discovered and thawed by the Challenger Foundation. As I said, the original character was a pretty run-of-the-mill golden age hero, but I'm having a whole lot of fun with him as the ultimate man out of time. He's been stone so long that not only are all his family members dead, but he has no conceivable way to track his descendants, if any. His country and culture has disappeared, all of the gods that he served devoutly (and received powers from) are extinct, and even his native language is dead. Since he was a vigilante in a rougher, more bloodthirsty time, he comes across as a barbarian to his teammates, even though his values were once considered the apex of civilization. Things that we take for granted seem incomprehensible to him, if not outright magical. I'm not just talking technology, either; in the story I just finished, I got to write a scene of him arguing with a instructional computer program over Heliocentrism vs. Geocentrism. I've been enjoying it immensely.
Anyway, I was wondering if anyone knows of any other appearances of Dart? I know he appeared in Volume II of Project Superpowers, but I don't think he uttered a word. He doesn't seem to be particularly popular or well known as far as public domain characters go.
Subject: Any appearances of Dart? 
