Master
   Traveller

 The hands were whirling around the dial from right to left with inconceivable rapidity. In this whirl we ourselves seemed to be borne along. Eternities seemed to contract into minutes while lifetimes were thrown off at every tick. 

Edward Page Mitchell, Master Traveller

In Lost Giants of American Science Fiction, sf historian Sam Moskowitz cites Mitchell as the first to spearhead five important sf themes in his anonymously published, syndicated short stories for the newspapers. One of those themes was the idea of a mechanism (rather than a dream or trance) to take a person back in time, as presented in “The Clock That Went Backward”—the first time machine! Another time travel innovation of Mitchell was the time traveling ghost from the future in “An Uncommon Sort of Spectre,” who unlike Dickens’s ghosts could interact with the time he traveled to.

 According to the view of things above adverted to, the different stages in the history of our race are not successive only, but are also co-existent and co-extensive with each other. Just as in a block of marble, there is contained, not one only, but every possible statue, though, of the whole number, only one at a time can be made evident to our senses; so, in a given region of space, any number of worlds can co-exist, each with its own population conscious of only that world, or set of phenomena, to which their ego is attuned.