Book:H. van Etten/Récréations Mathématiques/Historical Note
Historical Note on Récréations Mathématiques by H. van Etten
It has never been definitely established who H. van Etten was.
The usual belief is that it was Jean Leurechon, although there is no concrete evidence to back that up for certain.
Some sources believe that Henry van Etten, or Henrik van Etten, may have been a student of Leurechon.
Some go further and declare that, while attributed to this unknown student, it was in fact still (at least mostly) written by Leurechon, but that the latter had graciously allowed van Etten to put his name to it.
There is another school of thought that believes it may actually have been Jean Appier Hanzelet, who was the printer, and whose name is all over it.
This is supported by the fact that Hanzelet was demonstrably accomplished in much of the science described in this book, in particular fireworks and military techniques.