Camera Lucida

Optical instrument depending for its action upon the principle of internal total reflection. By its means the outlines of objects may be traced as projected by the eye upon a sheet of paper. Invented by Wollaston 1804 and improved by Amici. Amici's consists of a triangular gla prism, right angled at B. One of its perpendicular faces is turned toward the object that has to be drawn and the other life, which was spent in poverty. IMG:content-0698.png:[graphic] IMG:content-0699.png:[blocks in formation] Luis de Camoens.