A DUTCH BAROQUE MAGIC PROJECTION DEVICE (TOVERSPIEGEL), MID-18TH CENTURY

By repute Bartholomeus Weddik Wendel (1746 - 1825), who was a member of the Physics Department of Felix Meritis in Amsterdam;

Margaretha Johanna Weddik Wendel (1786 - 1817), married to Hieronymus Nicolaas Baron van Slingelandt (1787 - 1844);

Hieronyma Maria Antonia Fortunata Baronesse van Slingelandt (1814 - 1875), married to Jhr Jacob Pieter Teding van Berkhout (1810 - 1892);

Jkvr Catharina IsabellaTeding van Berkhout (1837 - 1886), married to Jean Antoine Corneille Bosch Reitz;

Sigisbert Chrétien Bosch Reitz (1860 -1938);

his godson Jhr Gijsbert Christiaan Six van Wimmenum (1892 - 1975);

Thence by descent

The method of making mirrors out of plate glass was invented by 13th-century Venetian glassmakers on the island of Murano, who covered the back of the glass with an amorphous coat of tin using a fire-gilding technique. Especially from the sixteenth century onwards, Venice became the centre of mirror manufacture, which installed in richly decorated frames served as luxury decorations for palaces throughout Europe. During the 17th century, the secret of the mercury process eventually also arrived in other places in Europe which led to a more large-scale industrialization of the process, eventually making mirrors more affordable to the masses. The mercury's toxicity - a primary ingredient in gilding, which was boiled away forming noxious vapours - however remained a severe problem. Although the present magic projection device may not look that impressive to modern eyes, in the 18th century it was quite an achievement – surely also expensive - to make a smooth concave mirror of this size.

The 17th century saw the development of an immense interest in optics - i.e. the various uses of lenses and mirrors - and Dutch scientist from the so-called ‘Golden Age’, such as the famous mathematician, astronomer, and physicist Christiaan Huygens, played a prominent role. Apart from being useful to scientists, optical instruments were also very popular entertaining curiosities with people who could afford them. ‘Phantasmagoria’ was a form of horror theater which during the 18th century became very popular in Europe that used mirrors, magic lanterns etc. to project frightening images, especially of ghosts. It is noteworthy to mention that an 18th century hand-written document in the Six archive which possibly refers to the present device, apart from giving a scientific explanation, is titled ‘Om Spook te maaken met twe Brant Spiegels’ (to make a ghost with two focal mirrors).

Another possibility is that the present device perhaps was used as a painter’s tool. Recent research into Renaissance masters such as Vermeer and Rembrandt, have further substantiated the theory that various artists used optical aids such as the camera obscura, camera lucida, and mirrors, to achieve photorealism in their paintings. In this respect it is important to note that concave mirrors project images, but with the advantage for an artist that they maintain the parity of a scene.