Polemoscope, 18th century

An Englisch polemoscope or jealousy glass, 18^th century. Made of turned lignum vitae wood. Brass bound and 10 cm long, This rare optical device has viewing apertures in each end, 45° mirrors inside placed in red seal, and an observation port on either side. One of the two end has a low telescope. By looking in either end one can surreptitiously view at 90° to the line of sight. Condition is good, complete with worn card case. This form op Polemoscope or jealousy glass was apparently most appreciated for viewing suitors at the opera house, but few examples have survived.