Catholic Encyclopedia: Nicolaus Steno - Or Niels Steensen. Danish anatomist and geologist who converted to Catholicism. Was made a bishop. He died in 1686. Nicholas Steno (1638-1686) - Essay on Steno's contributions to geology and particularly to the theory of fossil formation. Engines of Our Ingenuity: Nicolaus Steno - 3 1/2-minute radio program in RealAudio, and a transcript, about the scientist who was fascinated by the question of solid formations within rocks. History of Geology: Nicolaus Steno - An introduction, for adults, to this anatomist and his contributions to geological theory. Nicolas Steno - Biographical article on the scientist and bishop beatified by the Catholic Church. Niels Stensen - Although he sometimes relied on theories later discredited, this scientist established some basic principles still in use today. Short essay on the man and his discoveries. Stensen, Niels - Six-page entry from the Dictionary of Scientific Biography, including bibliography, by Gustav Scherz. Site also has a digitized version of the Prodromus, in Latin.