The first chapter of Émile Zola's Nana (1879) is set in a theater. I was engrossed at once, but ... what was this about twins? Hey, twins again! Why are there so many twins in this theater? And showing up in the oddest places, seriously!
For instance, "Fauchery, qui avait pris sa jumelle, regardait la comtesse ..."
He... looked at the countess, having taken her twin sister to the theater? I thought he came in with la Faloise!
This was the last straw. The last twin, as it were.
But alas, Harper-Collins only confirmed my confusion: jumelle was indeed the feminine of jumeau, and it did indeed mean "twin."
And then my eye wandered down from jumeau and saw jumelles (npl): binoculars.
Well, that makes more sense.