"Newton's Large Prism By Duboscq, C. 1870"
Triangular prism called Newton used in experiments of diffraction or decomposition of light. The large prism is mounted in a brass triangle connected to a wheel allowing it to pivot on itself. The prism no longer has its sliding foot. Good size, it measures 9cm in height and 5.7cm on the side. Despite some chips in the corners and on the edges, fairly good condition and perfect used condition. Beautiful French signature of a specialist manufacturer of laboratory optical instruments from the second half of the 19th century. 
Le Magazine de PROANTIC
TRÉSORS Magazine
Rivista Artiquariato