Physiognotrace c1798 Portrait Miniature

Rare French Physiognotrace c1798 Portrait Miniature
 
A delightful print dating from the end of the 18th century made using a little known instrument called a physiognotrace.
 
A physiognotrace is an instrument, designed to trace a person's outline to make semi-automated portrait prints. It was invented in France in 1783–84 and popular for some decades. The sitter climbed into a wooden frame (1.75m high x 6.5m wide), sat and turned to the side to pose. A pantograph connected to a pencil produced within a few minutes a "grand trait", a contour line on a piece of paper. With the help of a second scaling down pantograph, the basic features of the portrait were transferred from this sheet in the form of dotted lines to a copper plate which had previously been prepared with a ground for etching. One week later the sitter received an etched plate and twelve little prints of which this is one.
Credit Wikipedia
 
Condition
Excellent. Presented in a beautiful heavy cast frame.
 
Size
5.5cm diameter (10cm to the top of frame)
2.25 inches diameter (4 inches to the top of frame)