The Horse in Motion

Eadweard Muybridge’s 1878 photographic sequence of a galloping horse settled a long-standing debate: does a horse ever have all four hooves off the ground simultaneously? The answer, revealed through sequential photography, was yes.

While not a data visualization in the traditional sense, Muybridge’s work established the principle of small multiples applied to temporal data — showing change through a sequence of aligned frames. Edward Tufte later cited it as a foundational example of this technique.

The series also pioneered the idea that visualization could reveal truths invisible to the naked eye. The human eye cannot resolve the motion of a galloping horse, but a systematic visual recording can. This principle — that visualization makes the invisible visible — remains central to the field today.