Spectroscope

Jules Duboscq began making spectroscopes soon after Robert Bunsen and Gustav Kirchhoff announced their pioneering observations in this field, and by 1863 he could boast of having supplied instruments of this sort to numerous chemical laboratories and cabinets of physics. In this example, used at the U.S. Military Academy, the medium arm holds the slit facing the light source, the short arm holds a linear scale, the long arm holds the viewing telescope, and the central platform holds the prism that dispersed the light into a spectrum. The inscription reads “J. Duboscq / à Paris / No. 303.”