This paper explores the hoarding, collecting and occasional display of old apparatus in new laboratories. The first section uses a 1936 exhibition of Cambridge’s scientific relics as a jumping-off point to survey the range of historical practices in the various Cambridge laboratories. This panoramic approach is intended to show the variety and complexity of pasts that scientists had used material to conjure in the years prior to the exhibition. Commerce and commemoration emerge as two key themes. The second part turns to the Cavendish Laboratory (experimental physics) to explore the highly specific senses of time and memorialization at play in the early years of the laboratory (circa 1874–1910), and the way these were transformed over the subsequent generations leading up to the 1936 moment. The key figure here is James Clerk Maxwell, whose turn to history involved a mix of antiquarianism and modernism. The paper concludes with an attempt to characterise the meanings and significances of ‘the museum in the lab’. This phenomenon ought to be understood in terms of the wide range of ‘collections’ present in laboratory spaces.