The Dartmouth Biomedical Libraries

The Harmonograph by Don Fitzpatrick

A harmonograph is a mechanical apparatus that employs pendulums to create a geometric image. The drawings it creates are called Lissajous curves. The harmonograph was invented in 1844 by Hugh Blackburn, a professor of mathematics at the University of Glasgow. The harmonograph used to create the images in this exhibit employs three pendulums to control the movement of a pen relative to a drawing surface. Two linked pendulums move a pen in a circular motion along one axis and the third pendulum moves the drawing surface in a rotary motion along a perpendicular axis. By varying the frequency and phase of the pendulums relative to one another different patterns are created.  Don Fitzpatrick built the harmonograph used in this exhibit based on several different designs in order to make a machine that could be portable and multi-functional.  When not being used as a drawing machine the device can be disassembled and used as a coffee table.  This exhibit features many different types of drawings (harmongrams) using a variety of inks, colors and paper. The exhibit will be on display through July.

• Video of the harmonograph creating a drawing.
• DHMC Spring Art Exhibit

About the Artist:
Don Fitzpatrick is the IT Specialist for the Dartmouth Biomedical Libraries and also a member of the Steering Committee for Twin State MakerSpaces, a non-profit organization currently in the planning and development stages of two makerspaces in the Upper Valley (The Claremont MakerSpace and The Upper Valley MakerSpace.)  Don enjoys spending his spare-time making stuff in his workshop, music studio, and kitchen.  Some of his recent projects include woodworking, microcontrollers, and synthesizers.