A pantograph armed with cutting-files a which carve the relief out of a block of gypsum, was employed in1893-1900by C. Perron of Geneva, in producing his relief map of Switzerland on a scale of 1: ioo,000.
3 Kienzl of Leoben in 1891 had invented a similar apparatus which he called a Relief Pantograph (Zeitschrift, Vienna Geog.
Curve to a scale enlarged in the ratio ab: ac. This property of the parallelogram is utilized in the construction of the pantograph, an instrument used for obtaining a copy of a map or drawing on a different scale.
Mechanism; so that, if b is guided in any curve, the point a will describe a similar curve turned through an angle baa, the scales of the curves being in the ratio ab to cc. Sylvester called an instrument based on this property aplagiograph or a skew pantograph.