Nicholas Jardine offers here an edition and the first translation into English of Johannes Kepler's A Defence of Tycho against Ursus. He accompanies this with essays on the provenance of the treatise - the circumstances which provoked Kepler to write it, an analysis of its strategy, style and historical sources and of the contents of Ursus' Treatise on Astronomical Hypotheses to which Kepler was replying. Dr Jardine also provides three extended interpretive essays on the intrinsic interest and historical significance of (...) the work. (shrink)

The ArgumentIt is often assumed that all sciences travel the path of increasing precision and quantification. It is also assumed that such processes transcend the boundaries of rival scientific disciplines. The history of the personal equation has been cited as an example: the “personal equation” was the name given by astronomers after Bessel to the differences in measured transit times recorded by observers in the same situation. Later in the nineteenth century Wilhelm Wundt used this phenomenon as a type for (...) his experiments on reaction times. For historians of psychology, this has been taken to be an exemplary case where quantified laboratory science rescued astronomy by showing that this was really a psychological phenomenon measurable only in complication experiments. This paper challenges this story. Astronomers neither ignored, nor despaired of, the personality problem. Instead, the managers of the great observatories developed a new chronometric regime of vigilant surveillance of subordinate observers. The astronomers' solution was thus intimately connected with social and material changes in their way of life: a division of labor in the observatories, a network of observing sites, a mechanization of observation. The paper documents these changes and then presents a study of one case where managers, amateurs, and psychologists clashed for authority over the personality problem. Measurement is given its meaning when situated in specific contexts of styles of work and institutions. Disciplines give meanings to values, and often resist attempts by others to redefine these meanings or to gain authority over measurement. Quantification is not a self-evident nor inevitable process in science's history, but possesses a remarkable cultural history of its own. (shrink)

In his comprehensive survey of the work of William Herschel, published in the Annuaire du Bureau des Longitudes for 1842, Dominique Arago argued that the life of the great astronomer ‘had the rare privilege of forming an epoch in an extended branch of astronomy’. Arago also noted, however, that Herschel's ideas were often taken as ‘the conceptions of a madman’, even if they were subsequently accepted. This fact, commented Arago, ‘seems to me one that deserves to appear in the history (...) of science’. From the time Herschel published his first paper in the Philosophical transactions in 1781, he was subjected to the suggestion of lunacy. His patron and friend William Watson, told him that after his claims for the extraordinary power of his telescopes, ‘your prognosis that some would think you fit for Bedlam has been verified’. On learning of Herschel's supremely accurate new micrometer, the astronomer Alexander Aubert exclaimed to Herschel that ‘we would go to Bedlam together’: Aubert wrote to Herschel in January 1782 that he should ‘mind not a few jealous barking puppies: a little time will clear up the matter, and if it lays in my power you would not be sent to Bedlam alone, for I incline much to be of the party’. (shrink)

The ArugmentThis essay answers a single question: what was Robert Hooke, the Royal Society's curator of experiments, doing in his well-known 1665 work,Micrographia?Hooke was articulating a “universal cure of the mind” capable of bringing about a “reformation in Philosophy,” a change in philosophy's interpretive practices and organization. The work explicated the interpretive and political foundations for a community of optical instrument users coextensive with the struggling Royal Society. Standard observational practices would overcome the problem of using nonstandard instruments, while inherent (...) inrepresentation– the interpretive practice championed in the text – were important theological and political meanings. Hooke's kind of experimental philosophy undermined the claims made by “atheists” and “enthusiasts” – the enemies of the restored church and state – while also producing useful knowledge. Equally important, Hooke modeled the community described inMicrographiaupon the classicalres publica, but his community made important concessions to Restoration political realities, especially the growing role of commercial or transactional relationships. (shrink)

This article places the famous images of Johannes Hevelius's instruments in his Machina Coelestis in the context of Hevelius's contested cometary observations and his debate with Hooke over telescopic sights. Seen thus, the images promote a crafted vision of Hevelius's astronomical practice and skills, constituting a careful self-presentation to his distant professional network and a claim as to which instrumental techniques guarantee accurate observations. Reviewing the reception of the images, the article explores how visual rhetoric may be invoked and challenged (...) in the context of controversy, and suggests renewed analytical attention to the role of laboratory imagery in instrumental cultures in the history of science. (shrink)

ArgumentThe British Astronomer Royal, Nevil Maskelyne, spent four months on a Scottish mountainside in 1774, making observations of zenith stars and coordinating a detailed survey of the size and shape of the mountain Schiehallion, in order to demonstrate and quantify what was known as “the attraction of mountains.” His endeavors were celebrated in London, where it was stated that he had given proof of the universality of Newtonian gravitation and allowed for a calculation of the relative densities of the earth (...) as a whole and the earth near its surface. This paper argues that the “Schiehallion Experiment” was as much a trial of the precision of Maskelyne's instruments and their expert management as it was a trial of Newtonian theory. By tracing the biography of the key instrument used by Maskelyne, his zenith sector, we see how much personal credibility was a stake for him in Scotland. By considering the mountainside as a place to test and reveal the precision of astronomical instruments we see a link between the Scottish endeavors and Maskelyne's ambitions for the Greenwich Observatory. (shrink)