'Bummock: Tennyson Research Centre' is an artistic research project involving three artistic researchers: Andrew Bracey, Danica Maier and Sarah Bennett. A bummock is the unseen — submerged — part of an iceberg, and comprises the largest volume of ice, compared with the tip — which is visible above the surface of the water. Likewise, archives hold more items than are commonly viewed or accessed. In Bummock, we choose to bypass the catalogue to engage with materials directly, establishing a 'controlled rummage' method as an alternative approach to standard archive access practice.