Johan Rudolff von Graffenried (1584--1648), an \textit{unknown} ``compilator'' from Bern (Q2912407)

Some years ago, the present author discovered at a second-hand market in Geneva a book published in 1619. It was \textit{Arithmeticae Logisticae Popularis Libri IIII}, by J. R. von Graffenried H. B. (Helvetus Bernensis: Swiss from Bern). The book contains nearly 800 pages and may be considered as an advanced guide to arithmetic compiled from works of more than 40 authors with Pythagoras, Aristotle, and Euclid among them. The paper under review gives a brief account on life and activities of J. R. von Graffenried and tries to answer the naturally arising question: why was this useful book practically unknown for more than 400 years?NEWLINENEWLINEFor the entire collection see [Zbl 1242.01001].