"Baradelle - Two Brass Rulers, 18th Century"
A set of two 18th-century brass folding rulers: - A six-inch (half-foot) folding ruler by Baradelle in Paris, circa 1740. This is almost certainly by Nicolas Jacques Baradelle. The instrument measures 8.7 x 2.2 cm when closed. Wear and stains. - A twelve-inch (one-foot) folding ruler, also forming a set square, unsigned, and divided into twelve inches. The ruler measures 17.4 x 2.4 cm when closed. Good condition. 
Le Magazine de PROANTIC
TRÉSORS Magazine
Rivista Artiquariato