Pre-photographica: CAMERA LUCIDA
The Camera Lucida was invented by the British scientist William Hyde Wollaston (1766-1828) in 1806/1807.  It is an aid to drawing, not a camera. When the artist looks through the prism he sees both the drawing board and the subject he wants to draw. He now fills in the image in correct perspective. The camera Lucida is not easy to use. The skills of the artist determines the result. When looking both at motif and drawing through the prism you can only see a part of the motif that means that the camera Lucida has to be realigned several times.        
The upper part of the camera lucida with the small prism and the lower part with the clamp. The makerīs name Charles Chevalier is engraved on the clamp.