In this dissertation, I examine astronomical practice in the second half of the seventeenth century by analyzing the nature of observation and instrumentation within an institutional and social context. I argue that astronomical practice was transformed by the convergence of several overlapping factors including the deployment of new instruments, the mathematical and astronomical education of practitioners, the gradual assimilation of new ideas, and the rise of scientific societies and networks. More specifically, I argue that the 1670's controversy between Johannes Hevelius and Robert Hooke and the ensuing debate that involved a larger circle of practitioners, helped establish a new foundation for the discipline of astronomy. In forcing practitioners to take sides, the controversy prompted them to define the precise nature of astronomical practice as well as the necessary qualifications for its practitioners. In Chapter 1, I discuss sixteenth and seventeenth-century astronomical instruments, and I provide a history of instrumentation from the use of positional measuring instruments in the late sixteenth century to the more widespread use of micrometers and telescopically-mounted positional measuring instruments in the late seventeenth century. Proceeding from the instruments to the people involved, in Chapters 2 and 3 I discuss the mathematical and astronomical community of the late sixteenth to late seventeenth centuries. The "community" included those individuals working both within and outside the universities. In Chapter 4, I discuss the Hevelius-Hooke controversy over the relative merits of naked-eye versus telescopic sights as the watershed in positional astronomy that defined the role of astronomers, shaped their methods of observation, and directed future research. In the final chapter of this study, Chapter 5, I discuss the work of Cassini at the Paris Observatory and Flamsteed at the Greenwich Observatory, and how their efforts were shaped by the Hevelius-Hooke controversy. / Ph. D.

<p>This essay revolves around <em>Micrographia </em>written by the English 17th century experimental philosopher Robert Hooke and the way it mediated microscopic experience. The focus of this study is on one hand the strategies Hooke used to communicate experience and on the other the responses by some of Hooke’s contemporary readers. By comparing <em>Micrographia </em>to Henry Power’s <em>Experimental Philosophy</em>, we see that <em>Micrographia </em>uses images where the author is invisible and textual narrations with an explicit authorial voice to mediate experimental experience to his contemporaries. Samuel Pepys uses the mediated experiences to learn how to see through the microscope and to become more like the author in <em>Micrographia</em>, Margaret Cavendish does not trust the representational techniques of Hooke and the playwright Thomas Shadwell satirizes the gentleman virtuoso that constitutes the narrative voice in <em>Micrographia</em>. By the study of these three readers, I build on Peter Dears definition of a scientific text as having an inherent reference to an experimental situation. By seeing <em>Micrographia </em>as defined through the interactions between the author and the readers, we see that this reference, and therefore a text’s scientific status, is defined by a relation between author and reader based on trust. The reader has to trust both the author and the representational techniques used in the text. The appropriation of <em>Micrographia </em>by readers who do not possess this trust, results in the redefinition of <em>Micrographia </em>into other kinds of texts that fill different purposes defined by the readers. <em></em></p>

This essay revolves around Micrographia written by the English 17th century experimental philosopher Robert Hooke and the way it mediated microscopic experience. The focus of this study is on one hand the strategies Hooke used to communicate experience and on the other the responses by some of Hooke’s contemporary readers. By comparing Micrographia to Henry Power’s Experimental Philosophy, we see that Micrographia uses images where the author is invisible and textual narrations with an explicit authorial voice to mediate experimental experience to his contemporaries. Samuel Pepys uses the mediated experiences to learn how to see through the microscope and to become more like the author in Micrographia, Margaret Cavendish does not trust the representational techniques of Hooke and the playwright Thomas Shadwell satirizes the gentleman virtuoso that constitutes the narrative voice in Micrographia. By the study of these three readers, I build on Peter Dears definition of a scientific text as having an inherent reference to an experimental situation. By seeing Micrographia as defined through the interactions between the author and the readers, we see that this reference, and therefore a text’s scientific status, is defined by a relation between author and reader based on trust. The reader has to trust both the author and the representational techniques used in the text. The appropriation of Micrographia by readers who do not possess this trust, results in the redefinition of Micrographia into other kinds of texts that fill different purposes defined by the readers.