Pantograph

A linkage invented in 1630 by Christoph Scheiner for making a scaled copy of a given figure. The linkage is pivoted at ; hinges are denoted . By placing a pencil at  (or ), a dilated image is obtained at  (or ).

REFERENCES:

Cundy, H. and Rollett, A. Mathematical Models, 3rd ed. Stradbroke, England: Tarquin Pub., pp. 232-233, 1989.

Coxeter, H. S. M. Introduction to Geometry, 2nd ed. New York: Wiley, pp. 69-70, 1969.

Durell, C. V. Modern Geometry: The Straight Line and Circle. London: Macmillan, p. 5, 1928.

Wells, D. The Penguin Dictionary of Curious and Interesting Geometry. London: Penguin, pp. 167-168, 1991.