2021 Annual Meeting

Time and observatories

The histories of time and of astronomical observatories are woven tightly together. Since the early days of positional astronomy, clocks have been as important as telescopes in tracking and charting celestial bodies. The rotating Earth, measured at observatories by telescopes, was our measure of time.

By keeping time accurately and precisely, observatories became recognised as centres of time measurement and, as time became an increasingly valuable commodity in the ages of imperial expansion and industrial development, observatories found themselves with a new public role: providers of time signals.

A further role grew up in some observatories – the testing and rating of watches and chronometers, either for national navies or for the watchmaking trade. Observatory time had value and status, though not always without controversy.

The stories of some observatories, such as Greenwich, have been widely told in the English-language literature, but many astronomical institutions around the world are less well known. The circulation of people, techniques and technologies around a global network of observatories and the manufacturers that supplied them with instruments is often overlooked.

And studies of rivalry as well as collaboration offer fascinating insights into the social, cultural and political histories of these pioneering scientific institutions. 

It was a desire to learn about time and observatories besides the familiar example of Greenwich that prompted the theme for this Annual Meeting, which will be held online via Zoom on Saturday 15 May 2021.

The event comprises three sessions: the morning lectures, the AGM, and the afternoon lectures. Please register separately for each session you wish to attend – the links are below. This means that to attend the whole day, you need to make three registrations. You will receive Zoom links once you register. The event is free to attend and open to all, although only AHS members may vote in the AGM.

Saturday 15 May 2021


10.30 Chair’s introduction

10.35 David Rooney, 'Observatories, prestige and power politics, from Hulagu Khan to the Space Race’ (this talk replaces the advertised paper by Rossella Baldi, ‘Discovering chronometry: the origins of the Neuchâtel Observatory’ – Rossella regrets that she has had to withdraw from the meeting in unavoidable circumstances)

11.10 Simon Schaffer, 'Doing time: clocks and cosmology in the Australian penal colony'

11.45 Peter K. Thomas, 'Clockwork-related technologies used in astronomical observatories'

This session will be an online Zoom Webinar. To attend, please register here.

12.15 Break for lunch


14.00 Annual General Meeting, and presentation of awards by Patricia Fara

This session will be an online Zoom Meeting. To attend, please register here.


15.00 Lee Macdonald, 'The watch and chronometer-rating service of Kew Observatory, 1880s–1912'

15.35 Edward Gillin, 'Guns, bells, clocks, and balls: transmitting observatory time through sound and vision across Victorian Britain'

(We regret that the paper by Paolo Brenni, 'The Italian way to modern time standards', will not be presented at this meeting owing to unavoidable circumstances.)

16.10 Closing words

This session will be an online Zoom Webinar. To attend, please register here.