"Walnut And Brass Board, France, 18th Century"
Rare full circle, called a planchette, with four pinnules, two of which are movable, mounted on a rotating alidade. The instrument is made of walnut and brass. The large brass circle is divided into two 360th degrees, then every degree and half-degree. An eccentric compass is equipped with an arrow-shaped needle. The ball joint is missing. Rare model of topographical circle. 24cm in diameter. 
Le Magazine de PROANTIC
TRÉSORS Magazine
Rivista Artiquariato