For the most part, this story is about a cantankerous inventor who merely listens in on past historical events—which, of course does not qualify as time travel. But there is that for-the-most-part part.
Thor, will you please take care of. . .

Variants

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  1. “Famous First Words” by Harry Harrison, Magazine of Fantasy and Science Fiction, January 1965.
    2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . written by Harry Harrison