LE SPECTOGRAPHE. ~ No 2. [Paris, c. 1870s].
Square 8vo (175 × 150), folding cloth backed portfolio enclosing a hinged glass screen, a wooden drawing panel and a portfolio of 4 sample prints and several partially completed blank drawing sheets, wooden pencil (probably supplied). Covers with brass eyes, the upper cover with illustrated instruction panel. A couple of small wormholes to wooden panel and one print, covers slightly rubbed.
A simplification of the camera lucida method of duplicating images by drawing their reflection in a plain glass screen place perpendicularly to both the image to be duplicated and the drawing surface. Under the right lighting it is surprisingly effective. We can find no library examples of this apparatus (or of the ‘Spectographe No. 1’ which presumably preceded it.