An interesting item is in the “Buntes Allerlei” from March 28, 1918, which talks about the number of speakers of English, German, Russian, French, Spanish, and Italian, in that order from 160,000,000 English speakers, down to 50,000,000 Spanish speakers. This Eurocentric view overlooked speakers of languages from other parts of the globe, notably Mandarin, which then as today is the most widely spoken world language.
University of Wisconsin–Madison