Chappe Track Code

Before the telegraph was invented and popularised for messaging, multiple other ways of long distance communication were implemented. One of them was ‘le Systeme Chappe‘. Invented by Claude Chappe in late 1700s, it would convey information by means of visual signals formed by mechanical pivoting elements.  The way it worked is alphabets were assigned to the unique fixed positions of mechanical arms and thus information could then be encoded to be sent over distances.

Under this course of Physical Computing , we tried to explore and extract a new piece of information from the existing system. We asked ourselves: being able to send and receive alphabets by means of individual arm positions is side to this; but what if we could read in between the lines? Just like in music, where the transitional space between two individual notes is as important as the singular notes themselves, what if we could ‘read in-between the alphabets’?

How it was created

A robotic system mimicking the of Chappe semaphore tower was built. Then, multicolour LEDs were planted at four ends of the pivoting arms. When words were sent to the robot, it would cycle through each of the alphabets of the words. This motion, shot with long exposure photography to generate our final imagery.