Abstract: A multi-purpose drawing instrument comprising a guide rod supported horizontally on upright end supports and slidably engaging a roller support on a slide disc such that the disc is slidable along the rod. A carriage is slidingly supported on the guide rod above the slide disc and carries a conical member whose side wall is in pressure contact with the guide rod such that when the conical member is turned the carriage moves along the guide rod. The position of the carriage transversely of the guide rod can be adjusted and the carriage can be engaged with the slide disc when the carriage or slide disc is moved along the guide rod. A horizontally-disposed radial arm is rotatably connected to the center of the slide disc and it has a free end connectable to a ruler. The arm is capable of being clamped to the slide disc at any desired angle relative to the guide rod or carriage.