The author performed optical tests on four telescopes dating from the first half of the seventeenth century and on four objective lenses made by the Italian optician Giuseppe Campani. These tests consisted of the method of Ronchi and of the highly sensitive method of Foucault on an optical bench. The two incomplete surviving telescopes in Skokloster made by Wiesel have been reconstructed and compared with a telescope made by Divini and a telescope made by Campani. The contributions of Schyrl de (...) Rheita and Johannes Wiesel to the development of the telescope, and the influence of their new methods upon the opticians of the second half of the seventeenth century, especially Giuseppe Campani, are discussed. (shrink)

In his Paralipomena Johannes Kepler reported an experimentum that he had seen in the Dresden Kunstkammer. In one of the rooms there, which had been turned in its entirety into a camera obscura, he had witnessed the images formed by a lens. I discuss the role of this experiment in the development and foundation of his new theory of optical imagery, which made a distinction between two concepts of image, pictura and imago. My focus is on how Kepler used his (...) report of the experiment inside the camera obscura to criticize the account of image formation given in Giovanbattista Della Porta's Magia naturalis. I argue that this experiment allowed Kepler to sort out the confusion between images 'in the air'—referring to the geometrical locus of images in the perspectivist tradition of optics—and the experimentally produced 'projected images', which were empirically familiar but conceptually alien to perspectivist optics. (shrink)

Johannes Kepler. I. Permanence des traditions platoniciennes et aristotéliciennes. En 1635, parut dans la même ville de Prague, appauvrie et désolée intellectuellement par la Contre-Réforme, un ouvrage touffu intitulé Idearum operatricium ...

This essay proposes that the well‐documented interest in empirical and experimental practice at the early modern German courts was not limited to male practitioners. Just as princes evinced an interest in practical alchemy, mathematics, and astronomy, a large number of gentlewomen became expert medical practitioners. Using a case study of one noblewoman, Electress Anna of Saxony, I would like to expand the notion of “prince‐practitioning” to a more general and inclusive “court experimentalism.” Like the prince‐practitioners, Anna engaged in a laborious (...) attempt to learn the hands‐on techniques involved in becoming an expert; she collaborated with both noblewomen and noblemen in her efforts; and she semantically linked her medicine to the alchemical skills practiced by her husband, Elector August. Although court experimentalism cannot be equated with experimentation in the modern sense, medicine is one area in which women actively shared in the early modern fascination with empirical knowledge. (shrink)

In his Paralipomena Johannes Kepler reported an experimentum that he had seen in the Dresden Kunstkammer. In one of the rooms there, which had been turned in its entirety into a camera obscura, he had witnessed the images formed by a lens. I discuss the role of this experiment in the development and foundation of his new theory of optical imagery, which made a distinction between two concepts of image, pictura and imago. My focus is on how Kepler used his (...) report of the experiment inside the camera obscura to criticize the account of image formation given in Giovanbattista Della Porta's Magia naturalis . I argue that this experiment allowed Kepler to sort out the confusion between images 'in the air'—referring to the geometrical locus of images in the perspectivist tradition of optics—and the experimentally produced 'projected images', which were empirically familiar but conceptually alien to perspectivist optics. (shrink)

Introduction:Commerce and the Representation of Nature in Art and Science Pamela H. Smith and Paula Findlen Part 1. STRUGGLING WITH REALITY: Visualizing Nature and Producing Knowledge 1. Splendor in the Grass: The Powers of Nature and Art in the Age of Durer Larry Silver and Pamela H. Smith 2. Objects of Art/Objects of Nature: Visual Representation and the Investigation of Nature Pamela O. Long 3. Mirroring the World: Sea Charts: Navigation and Territorial Claims Alison Sandman 4. From Blowfish to Flower (...) Still Life Paintings: Classification and Its Images, circa 1600 Claudia Swan 5. "Strange" Ideas and "English" Knowledge: Natural Science Exchange in Elizabethan London Deborah E. Harkness Part 2. NETWORKS OF KNOWLEDGE: Commerce and the Representation of Nature 6. Local Herbs, Global Medicines: Commerce, Knowledge and Commodities in Spanish America Antonio Barrera 7. Merchants and Marvels: Hans Jacob Fugger and the Origins of the Wunderkammer Mark A. Meadow 8. Practical Alchemy and Commercial Exchange in the Holy Roman Empire Tara E. Nummedal 9. Time’s Bodies: Crafting the Preparation and Preservation of Naturalia Harold J. Cook 10. Cartography, Entrepreneurialism and Power in the Reign of Louis XIV: The Case of the Canal du Midi Chandra Mukerji 11. ’Cornelius Meijer inventor et fecit’: On the Representation of Science in Late Seventeenth-Century Rome Klass van Berkel Part 3. CONSUMPTION, ART AND SCIENCE 12. Inventing Nature: Commerce, Art and Science in the Early Modern Cabinet of Curiosities Paula Findlen 13. Nature as Art: The Case of the Tulip Anne Goldgar 14. Inventing Exoticism: The Project of Dutch Geography and the Marketing of the World, circa 1700 Benjamin Schmidt 15. Shopping for Instruments in Paris and London James A. Bennett EPILOGUES A World of Wonders, A World of One Lissa Roberts Questions of Representation Thomas DaCosta Kaufmann Contributors Index. (shrink)

Kepler's Somnium is a fantastical story about the world on the moon. It presents a heliocentric world-picture established through a total conversion of the meaning and place of observation in the hierarchy of knowledge. This epistemological program is construed through a critical adaptation of Lucian's "True Story," and Plutarch's "The Face on the Moon." Utilizing his new optics, embodied in the Camera obscura, Kepler inverts the meaning of these classical texts together with the reader's point of view. Astronomical knowledge is (...) vindicated and scientific observation is the only way out of an obscure and mannerist dream. (shrink)