A 6-inch reflecting telescope with speculum metal mirror, France, c.1750, signed "Passemant Ingenieur Royal Louvre Paris," black-painted brass, each end of the tube painted in gold with foliate and fleuron motifs, with brass and cast iron stand, the stand adjustable by means of an ivory-handled key, the tube 1380 mm long, the stand 400 mm tall, with cap.

PROBABLY THE LARGEST PASSEMANT TELESCOPE IN PRIVATE HANDS. In 1738, Passemant published a treatise entitled Construction d'un télescope de réflexion (Paris: P.N. Lottin, 1738). Later, he "won fame for his astronomical clocks, but was also well known for his terrestrial and celestial globes and his sundials, barometers, telescopes, and microscopes ... His inventive faculty earned him the title of 'ingénieur du Roi' ... and, in 1749, he was awarded quarters in the Louvre above what were then the premises of the Académie des Sciences" (Parker). He was responsible for three telescopes presented to the King in 1751, 1755, and 1759, and around that time he successfully incorporated a clock drive into a telescope.