A French rhodium or chrome plated brass camera lucida, P. Berville, Paris, circa 1900 With two-draw telescopic arm fitted with universal pivot carrying small glass prism inset into an oxidised carrier incorporating a slot to carry one from a choice of eleven glass lenses/slides present with the lot, the opposing end with thumbscrew clamp for fitting to the edge of a table incorporating lockable pivot for the arm and inscribed CHAMBRE CLAIRE UNIVERSELLE, MODELE DEPOSE, P. BERVILLE - 25 Chausee d’Antin. PARIS, in red velvet lined fabric covered case further stamped with makers name to the inside of the lid, the box 28cm (11ins) wide; with a German stainless and japanned steel planimeter, inscribed Maho No. 60, early 20th century, of Polar type with tracer and arm incorporating Vernier scale within frame incorporating measuring wheel, dial, support wheel and pivot for the pole arm terminating with pinned anchor weight, the pole arm inscribed Maho No. 60, in purple velvet lined fabric covered case, 26cm (10.25ins) wide, (2). The camera lucida allows an artis/draughtsman to trace the form of a three-dimensional object by viewing a reflection of the object via the prism and lens assembly connected to the end of the telescopic arm. The design was patented by William Hyde Wollaston in 1806 although the principals of the instrument had been outlined by Johannes Kepler in his Dioptrice in 1611.The planimeter allows the area of a shape to be measured by tracing around its outline and has historically proven useful in cartography and surveying photography. The polar planimeter was developed in 1854 by The Swiss mathematician Jakob Amsler-Laffon although the design had been pioneered by Johann Martin Hermann in 1814.