drawing instruments
Implements used in drawing, as distinguished from painting; particularly those used in geometrical, mechanical (architectural) drawing; the T square, straight edge, triangles, curves, rule or scale, compasses, dividers, ruling pen, dotting pen, and protractor are those commonly used; to which may be added such special contrivances as the centrolinead, ellipsograph, pantograph, spline, etc. (Sturgis, 1900)