In the latter half of the nineteenth century, as chronophotography made it possible to record movements, scientists began to dream of a comprehensive archive of moving phenomena. This research project will locate the vision of a moving-image encyclopedia within the longer history of archival fantasies of total knowledge. It will construct a history of the attempts to realize this dream over the course of the late-nineteenth, twentieth, and early twenty-first centuries, culminating with a consideration of the flourishing of such projects in the age of digital media. A guiding question will be why the promise of such a moving-image encyclopedia has been both so persistent and so difficult to realize.