Vues D'Optique: a collection of hand-coloured engravings depicting views in various European cities, namely Rome, Paris and the Hague comprising the Trevi fountain, Saint Peters Basilica, Porte Saint-Martin, the gardens at Versailles, Porte St. Denis, and the Buyten Hof (Hague); circa 1790, all approx. 29 x 41 cm; framed and glazed individually, each overall 49.5 x 62 cm. (6 items), Vue d'optique (French), vue perspective or perspective view refers to a genre of etching popular during the second half of the 18th century and into the 19th. Vues d'optique were specifically developed to provide the illusion of depth when viewed through a zograscope, also known as an 'optical diagonal machine' or viewers with similar functions.