When customers like Samuel Pepys visited the shop of Thomas Tuttell, instrument maker to the king, they could purchase a pack of mathematical playing-cards. The seven of spades, reproduced as Figure 1, depicted the diverse connotations of magnets, or loadstones. These cards cost a shilling, and were too expensive for many of the surveyors, navigators and other practitioners shown using Tuttell's instruments. They provide an early example of the products promising both diversion and improvement which were increasingly marketed to polite (...) audiences. Tuttell's description of loadstone as ‘a treasure of hidden vertues’ encapsulated many contemporary perceptions of these naturally occurring magnets which were to endure throughout the century. This phrase, with its hints of concealed financial and epistemological benefits, resonates with major eighteenth-century analytical themes, such as commercialization, the opposition between vice and virtue, and the fascination with the occult in the face of Enlightenment rationality. This card is emblematic of the multiple interpretations and utilizations of magnetic phenomena during the eighteenth century. It thus provides a useful starting-point for exploring some of the disputes which arose as enterprising individuals concerned with natural philosophy promoted themselves, their activities and their products. (shrink)

The presentation of nature as part of natural history is usually connected with a natural cabinet or natural history museum. A closer look at travel and field work, however, shows that display of nature as a spatial concept and material conditions begins already in the first moment of collecting objects, specimens, and economis news about a region to be investigated. In the year 1720 the German physician Daniel Gottlieb Messerschmidt was sent to Siberia by the Tsar Peter I of Russia (...) to explore this hithero terra incognita. During his travels Messerschmidt established two main instruments for collecting data and things, which I shall describe as organizing, material principles for his field work: written lists and notes, and boxes and cases. An analysis of these material objects and their specific uses reveals the intellectual and practical traditions in which learned activities and strategies took place in the beginning of the eighteenth century. (shrink)

This paper is concerned with the particular problems raised by observations of phenomena outside the common course of nature for their validation as knowledge. It examines to what extent the content of the reports and, in particular, their lack of intrinsic plausibility affected the methods used in their authentication and the assessment of testimony at the Royal Society in the first half of the eighteenth century. I show that literary strategies were usually necessary but not sufficient for the validation of (...) these kinds of observations. Next, I discuss why visual representations were especially useful in establishing the singularity of the observations, but I point out that their high costs and other restrictions meant that they were not so widespread. In contrast I show that, for a long period of time, testimony was used in the majority of the reports as the true stamp of authenticity. I note, however, that the Royal Society accepted reports by authors of varied social status, level of education and occupation, and I discuss some of the factors responsible for the complexity of the handling of testimony at the Society. I argue against Shapin that in the case of reports of extraordinary phenomena, the competence of the reporter and witnesses was often more important than their social status. The increasing role of expertise in the assessment of observations at the Society become especially apparent by the middle of the eighteenth century.Author Keywords: Authentication; Competence; Monstrous births; Singular; Testimony; Royal Society of London. (shrink)

Sometimes in the course of image-making, images are asked to represent unusual things. Around 1960, scientists and engineers working on the Computer-Aided Design Project at MIT began imagining that computers could be “active partners” to human designers. They began talking about a future of “human-computer symbiosis.” And they created a new type of image—the screenshot—that represented this new possibility. This paper describes early CAD research as a site for the emergence of the ideal of the interactive computer and how this (...) ideal was described and distributed through screenshots.Though we now routinely associate computers with interactivity, interactivity was beyond the average user’s experience in 1960.... (shrink)