The Material Culture of Astronomy in Daily Life: Sundials, Science, and Social Change

Abstract

Sundials are among the most ancient of astronomical instruments. The earliest surviving examples date from 1500 B.C. By tracing the length and angles of shadows and by employing mathematical projections of the celestial sphere, early dials marked the passage of time, the recurring seasons, and the apparent motion of the sun in the sky. They refl ected time consciousness. Sundials have also been time discipliners. Since Hellenistic times, they have been used to coordinate activities such as meals, prayers, and business. With the rise of commercial society in the late Middle Ages, a new sense of time pressure led to increased production and further development of sundials. Personal timepieces kept busy people on schedule. One goal of this paper is to show how the material culture refl ected changes in people’s experience of time consciousness, time discipline, and time pressure. A second goal is to explore the place of sundials in consumer culture. People acquired sundials, like other consumer goods, for many reasons: because they needed or desired them; or because the goods had symbolic value or projected a particular image of their owners (cf. Figure 1). As material goods, sundials offer instances of social hegemony, class structure, and regional taste. Their diverse mathematical forms and designs reveal how people spent their time and the degree to which religion and politics were valued. Historiographically, this is a new way of looking at old sundials. Often curators and sundial enthusiasts focus their attention on the mathematics of the different types of dials, the panoply of shapes and designs, or the craftsmanship of particular instrument makers. These are worthwhile projects and require considerable connoisseurship. I aim to go beyond these studies in order to explore not only the supply side, but also the demand side of the sundial trade. Mathematicians designed and instrument makers produced sundials to serve and please their customers. The three groups — mathematicians, makers, and consumers — were not in mutual isolation. Material culture was the link between theory, production, and consumption, and it sheds light on all. I take as my foundation a careful study of over two thousand historic sundials preserved in museums worldwide. Although literary evidence is useful, it is only by the close inspection and comparison of many dials from different places and periods that one can build a picture of astronomy and mathematics in daily life. Two great sundial collections are at the Adler Planetarium and Astronomy Museum in Chicago and the Harvard Collection of Historical Scientifi c Instruments. This paper will be illustrated by instruments in both museums. JHA, xxxii (2001)