Copyright: Leb茅e Inventaire G茅n茅ral / 脡cole Polytechnique
The goniometer designed by physicist and astronomer Jacques Babinet, measures the angular deviation of a light beam passing through an object or substance, and induced by the difference in optical index. This makes it possible鈥攊n mineralogy for example鈥攖o measure the refractive indices of crystals and the orientation of their crystallographic axes.