You have certainly heard of Pythagoras, yet none of this mathematician's writings have survived. By contrast, you may not know al-Battânî, although he left behind numerous works. Marie Crous's case is more troubling: few people know her name, and only one copy of her books survives. Until this spring, anyone wishing to read her Advis aux filles exersantes l’arithmétique (1636) and Abbregé de recherches (1641) had to visit the venerable Bibliothèque Mazarine in Paris and ask for volume 30047 to be retrieved from the stacks.
Now that these documents have been digitized and made available online, they are easier to access: we can all read these works (provided we adjust to the language of the 16th century), learn more about their author—the scant details of her life come from the prefaces—and discover her reading of Simon Stevin and her work as a mathematics tutor.
To access the two digitized works, search for "Marie Crous" on **bibnum.institutdefrance.fr**.
