I

n 1850, the American educator and transcendentalist Elizabeth Palmer Peabody set out to convert American schoolteachers to a new way of visualizing and recalling historical chronology. Her system, employing a thirty-by-thirty grid to be filled in with colors obeying a strict informational code, had a bold abstract look, and it made a bold claim: students trained in the system, Peabody said, would be able to instantly recall elaborate sequences of historical events and the relations among them. Blank, a Peabody chart looks like simple screen mesh; filled with colored paint, it looks a bit like a study for a Mondrian.

While the method proposed in Peabody's Polish-American System of Chronology is unfamiliar today, generations of students in Europe and America in the nineteenth century employed one or another version of it. These grid systems provide a window onto the study of history in the mid-nineteenth century, when old practices of memorization were being actively reimagined. They also give a glimpse into emerging information design. In them we find strong resonances with grid systems employed in the earlier Jacquard loom and the later Hollerith card, each of which answers related challenges in coding, compression, and retrieval, though in this case, the mechanism for coding and decoding is human not machine. The Peabody chart is something like a punch card for the mind.

Give it a try. How does history look and feel inside of Peabody's system?