Focusing on the Laboratory of Toxicology and Analytical Chemistry of the Faculty of Pharmacy at Cheikh Anta Diop University in Senegal, this article foregrounds temporality as a key dimension of the postcolonial history of African science. This laboratory, like many others across Africa, is experienced by its current and former members as a space of shortage. I explore how memories of ‘means’ and past scientific activity in Dakar and abroad give meaning to subsequent experiences of the lab as a place filled with inactive ‘antiques’ and ‘wreckage’. I suggest that the waning of means not only displaces scientific activity ‘elsewhere’ but also fragments its tempos, altering its rhythms along with its social, moral and affective qualities. The interpenetration of past and future generates nostalgia, segmented narratives and trajectories, quests for immediacy and continuity, as well as new engagements with routines of scientific regulation and management. Paying attention to the intersection of materiality and temporality – by taking seriously African scientists’ longing for science that moves forward, keeps pace, begins now and fills up time – thus opens up new ways of understanding what science means and what it means to do science in times of promise and decline, emergence and interruption, hope and uncertainty in postcolonial Africa.