Quantification and precision: a brief look at some ancient accounts.

We explore the extent to which ancient Greek authors formulated concepts that approximate or encompass our modern notions of precision and accuracy. First, we focus on estimates and measurements of geographic features, astronomical times and positions, and weight. These raise further questions about whether the quantities reported were measured, estimated, or rounded. While ancient sources discuss the use of instruments, it is not always clear that the aim was to achieve what we would today regard as 'precision'. Next, we briefly consider round numbers, observing that they could carry symbolic meaning, while unrounded numbers could give an impression of hard-won achievement. Finally, we examine uses of the word akribeia. This is often translated as 'precision' or 'exactness', and Greek writers sometimes used akribeia to denote an ideal for their inquiries. A brief look at its uses by a number of Greek writers will on the one hand show the mismatch with our term 'precision', and on the other hand throw some light on the aims of Greek investigators.

"Perhaps Irrelevant". The Iconography of Tycho Brahe's Small Gilt Brass Quadrant.

When Tycho Brahe published a description of his astronomical instruments in 1598 as part of a strategy to procure royal patronage, it was not with one of his grander, precision measurement tools that he opened his account, but rather a small brass quadrant with limited observational utility. The defining feature of this instrument was seemingly a small emblematic image inscribed within the arc of the quadrant. Through this symbolic motif Tycho conveyed a moralising message about the relative worth of astronomy. Considering a range of visual productions that may have influenced his iconography, the present paper situates the quadrant within the broader context of Renaissance visual culture and examines the significance of the quadrant in Tycho's wider instrument collection.

Introduction: Reengaging with instruments.

Over the past twenty years or so, historians of science have become increasingly sensitized to issues involved in studying and interpreting scientific and medical instruments. The contributors to this Focus section are historians of science who have worked closely with museum objects and collections, specifically instruments used in scientific and medical contexts. Such close engagement by historians of science is somewhat rare, provoking distinctive questions as to how we define and understand instruments, opening up issues regarding the value of broken or incomplete objects, and raising concerns about which scientific and medical artifacts are displayed and interpreted in museums and in what manner. It is hoped that these essays point historians of science in new directions for reengaging with scientific objects and collections.