I recently started reading the 1995 Penguin Popular Classics version of The Phantom of the Opera by Gaston Leroux. While reading it, however, I noticed that there is no attribution printed in the book as to who translated it. The book was originally published in French as Le fantôme de l'opéra.
I searched the copyright information in the front of the book. It mentions that it was first published in 1911. Wikipedia tells me that the first translation published in 1911 was translated by Alexander Teixeira de Mattos. Is this edition simply using the 1911 translation? Why wasn't Alexander de Mattos mentioned, in that case?
Who translated this version of the book, and why wasn't the translator acknowledged?