carbon bisulphide glass prism, angle 60 degrees, by William Ladd, London, England, 1870. carbon bisulphide glass prism 1870
Direct-vision dispersing prism consisting of two glass prisms enclosing a prism-shaped space for filling with a highly-refracting liquid Direct-vision dispersing prism
Adjustable angle liquid prism with detachable glass prism by Ducretet et Lejeune of Paris, C. 1870 Adjustable angle liquid prism with detachable glass prism by Ducretet et Lejeune of Paris