This workshop explores claims that knowledge and belief are inevitably and productively entangled. It is suggested that this kind of interweaving is peculiarly evident and important in work with objects that somehow respond to and register invisible forces, powers otherwise beyond observation and experience. Many devices have been charged with such a function. Machines that register and manage time seem peculiarly apt for consideration. The relation between knowledge and belief has a clear temporal dimension. Current knowledges are often used as standards against which past knowledge claims are dismissed, or appreciated, as systems of belief. It is as though the contrast between reliable engagement with nature and the worlds of cultural belief turns into a contrast between the future and the past. It is often claimed as part of the celebration of scientific modernity that as time passes culturally generated beliefs are systematically displaced by delocalised knowledge.