'From A Reader's Book of Days'

When was Frankenstein made? (The story, that is, not the monster.) The moment of Mary Shelley's creation has been nearly as enshrouded in legend as the "dreary night of November" when Victor Frankenstein gave the reanimating jolt to his monster. It was, as the story goes, a wet and dreary June in Switzerland when Lord Byron suggested to his guests—Dr. Polidori, who had just sprained his ankle, and the scandalously not-yet-married couple, Percy Shelley and Mary Godwin—that they each write a ghost story. As Mary Shelley recalled it later, after the men told their stories she had a vision in her bedroom of a scientist terrified by his own creation as it begins to stir with the spark of life. Terrified too by her vision, she rose to the sight of moonlight over the Alps, a detail that a Texas astronomer has, with methodical literal-mindedness, traced to a single possible hour for her inspiration, between two and three in the early morning of June 16.

- via