This thesis is about how empire shaped the everyday practices of astronomy and mathematics, and how the methods of these sciences came to be used to make historical claims about mythic events and races. I study how British scientific institutions in India became sites for producing new linkages between upper caste Hindus and a technical modernity, which proclaimed itself both European and unprecedented. Colonial rule is sometimes understood in terms of a black-and-white distinction between dominant imperial actors and a dominated colonial population, whose sphere of action was limited to passive participation. My interest is in historical actors and kinds of knowledge which trouble this distinction, in which the methods and the interests of both Indians and imperials is detectable. British rule in India was sustained by European claims to intellectual and technical superiority, which were not seperate from, but intricately related to, projects of political and economic domination. Achievements in mathematics and astronomy were no small part of this claim. I account for the changing relationship between modern and antiquarian knowledge by following a number of British surveyors in the Bengal Delta in the eighteenth century, who attempted to recover mathematical knowledge from Sanskrit texts. Back in London, these texts were studied by East India Company administrators, in the early nineteenth century, and mined for information valuable to a universal history of mathematics. As the British established hegemony over the subcontinent, Sanskrit astronomy was seen as a joke, a mere superstitious vestige. Yet it also qualified the Brahmins hired in Company observatories to produce new data. I show that observatories and universal histories alike were made to work by incorporating upper-caste labor and knowledge into the larger matrix of imperial power. By the end of the nineteenth century, a number of Indians tried to ``engraft" modern mathematical and observatory techniques onto Sanskrit astronomy. In tracing the day to day activities of observation and data collection required to regulate the multiple timescales of an empire, I show that practices of timekeeping exerted pressure on the cosmologies of both colonized and colonizer.