Originally published in 1934 as a supplement to the Style Manual of the United States Government Printing Office under the title Foreign languages for the use of printers and translators.
A treasure, especially for a language nut like me. This dense book describes over 100 languages, from Acholi, Afrikaans, Albanian, Amharic, and Anglo-Saxon to Yao, Yiddish, Yoruba, Zuñi, and Zulu. Some information and terms are dated — it was published in 1952 — but it's a wonderful resource.
There are even two pages on Glagolitsa, the oldest known Slavic alphabet, which "takes its name quite possibly from the Croatian and Dalmatian priests who used it in their liturgical services from about the 9th century and came from the Old Slavic word glagol, to speak".