Newsletter of the International Astronomical Union Commission C3 (History of Astronomy), edited and published semiannually at the Summer and Winter Solstices by Sara Schechner, Secretary of IAU Commission C3.

This is a story of the impact a collector can have on creating one of the world’s most celebrated of specialized museums. The museum is Harvard University’s Collection of Historical Scientific Instruments and the man responsible is David P. Wheatland of Topsfield, Massachusetts.

The publisher's print version is attached as a PDF.  The web version of the essay is here.

Time of Our Lives

Sundials of the Adler Planetarium

Sara J. Schechner

Published by the Adler Planetarium, with the support of the North American Sundial Society

The Adler Planetarium of Chicago has the best and most comprehensive collection of sundials and time-finding instruments in North America. Now many of these objects can be yours to explore. This volume encompasses a dazzling array of sundials, 268 in all, that date from the 15th to 20th centuries.

What makes this catalogue special is that it is written to engage non-specialists approaching sundials for the first time. Although the organizational logic is astronomical and mathematical, the primary Interpretive essays set the sundials into cultural and social context.

The catalogue divides sundials into classes according to the element of the Sun’s apparent motion that they track (e.g. hour-angle, altitude, azimuth, or a combination) and the orientation of the surfaces on which the hour lines are mathematically drawn. Within each chapter, the instruments are organized chronologically and by workshop, thereby giving readers insight into that type’s development over time and differences among makers. Technical object descriptions are supplemented by tables of divisions, gazetteers, saints’ days, weather forecasts, and in the case of polyhedral dials, the dial types, orientations, and hour systems drawn on every face. The tables offer a snapshot of the precision to which the maker aimed and the sundial’s complexity. Color photographs of each sundial show its overall appearance and details.

Chapter introductions go beyond mathematical descriptions of how each type works. Drawing upon research findings presented here for the first time, the essays offer insights into early production techniques, fads and fashions, social hierarchy among users, the impact of church and civil authorities, and the history of the sundial classes.

Throughout the ages, people’s sense of time has been influenced by their culture, politics, religion, labor, society, and geography. This catalogue offers concrete evidence, for every sundial in it embodies the time-related needs and values of its maker and users.

The catalogue includes a taxonomy of compass needles, glossary, bibliography, and index. It is hardcover, 488 pages, 9.75” x 11”.

Appendix III to “The Scientific and Historical Value of Annotations on Astronomical Photographic Plates”

The Scientific and Historical Value of Annotations on Astronomical Photographic Plates

Authors: Sara J. Schechner, David H. Sliski
Comments: 46 pages, 9 figures, Published in the Journal for the History of Astronomy, February 2016

arXiv:1602.03475v2 [physics.hist-ph]
DOI: 10.1177/0021828615624094
License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Subj-class: History and Philosophy of Physics (physics.hist-ph)

The application of photography to astronomy was a critical step in the development of astrophysics at the end of the nineteenth century. Using custom-built photographic telescopes and objective prisms, astronomers took images of the sky on glass plates during a 100-year period from many observing stations around the globe. After each plate was developed, astronomers and their assistants studied and annotated the plates as they made astrometric, photometric and spectroscopic measurements, counted galaxies, observed stellar variability, tracked meteors, and calculated the ephemerides of asteroids and comets. In this paper, the authors assess the importance of the plate annotations for future scientific, historical, and educational programs. Unfortunately, many of these interesting annotations are now being erased when grime is removed from the plates before they are digitized to make the photometric data available for time-domain astrophysics. To see what professional astronomers and historians think about this situation, the authors conducted a survey. This paper captures the lively discussion on the pros and cons of the removal of plate markings, how to best to document them if they must be cleaned off, and what to do with plates whose annotations are deemed too valuable to be erased. Three appendices to the paper offer professional guidance on the best practices for handling and cleaning the plates, photographing any annotations, and rehousing them.

Three supplementary appendices are available online here.