Baroness de Beausaleil

The correct spelling of this name is BEAUSOLEIL.

Baroness Martine de Beausoleil is perhaps the first female geologist and mining engineer. She and her husband, Jean du Châtelet, baron de Beausoleil, founded a mining company that used dowsing, an ancient technique involving a stick or rod, to locate mineral deposits. The two traveled Europe and, in 1626, were commissioned by King Louis XIII to search France, where they are said to have discovered several hundred mines. The baroness’ two reports on the subject, Véritable déclaration de la découverte des mines et minières and La restitution de pluton, were published in 1632 and 1640, respectively. Because the Church associated dowsing with witchcraft, both the baron and baroness were charged with sorcery and died in prison.