Professor Hoffmann (Angelo J. Lewis, 1839-1919) translated quite a few books into English, from their original texts in German and French. More specifically, he translated several from French, and he translated two (The Illustrated Book of Patience Games and The Game of Skat) from German.
It is more or less accepted as an axiom that a number of Hoffmann’s own works were translated into other languages, though when one starts to look into the topic, one does not necessarily find as many as one might expect. It is my understanding that at least “something” on conjuring by Hoffmann has been translated into French, Swedish, and Russian, and maybe Spanish.
Maybe it’s a “sour grapes” thing, but I have largely lost my youthful enthusiasm for the concept of finding translations of Hoffmann’s writings on conjuring. I do have a few such items, but my impression is that the typical translation does not start at page 1 of (say) Modern Magic and then proceed straight through to the end.
However, I was quite interested to learn of a couple of translations of card-game rule-booklets into foreign languages, namely German and Swedish. Information on a Swedish translation of Bridge Whist is found in the online catalog of the National Library of Sweden, as follows:
Regler för Bridge Whist, af professor Hoffman. : Antagna i engelska klubbar. Stockholm, 1903.
That can be translated as “Rules for Bridge Whist, by Professor Hoffman[n], Adopted in English Clubs.” I have essentially no further details on the book itself, but it is pretty evident that it is a translation of Hoffmann’s booklet entitled Bridge Whist.
At least one other translation of a Professor Hoffmann rule-booklet exists. I have a copy of it in my collection. The title page reads:
Aus dem Englischen übersetzt nach
Verlag von B. Dondorf G.M.B.H.
This can be loosely translated as: Bridge, translated from the English after Professor Hoffmann, Published by B. Dondorf, Limited Liability Company, Frankfurt.
More literally, it would be: Bridge, from the English translated after Professor Hoffmann, Published by B. Dondorf, Company With Limited Liability, Frankfurt on the Main River. But some of that is not really suitable for translation. For instance, the city’s name is Frankfurt am Main (usually known as Frankfurt.)
The book is 62 pages long.