It is a drawing apparatus which was invented in 1788 by Conrad Bernhard Meyer from Aurich, Germany,  to facilitate the creation of a mirror-inverted drawing for etching on a copper plate.

It is to be assumed, however, that this technique was already known in earlier centuries among painters, at least since it was possible to produce transparent flat glass.

The device consists of an ordinary glass pane, set in a frame, and a second frame, which is covered with paper and serves as a light screen.

To the left of the glass pane the drawing is placed, which one wants to copy, to the right of the glass pane the paper on which one wants to draw, and in front of it the screen is placed (see Fig. 4).

By now looking through the left side of the glass pane, one apparently sees the drawing or object to be copied on the drawing ground.

With slight modifications you can also use the tool to take a perspective picture of a landscape and to enlarge or reduce it.

 Moderen Version (Klick on image)