On 27 July, our symposium 'Empires of longitude: international perspectives on navigation, mapping and science' seemed to go down a storm at the 24th International Congress of History of Science, Technology and Medicine in Manchester. We had a full room including many people who admirably stayed the course through all three sessions. Richard previously posted the abstracts for the members of our team who were going to present, but I thought it might also be worthwhile to give an overview of the entire event after it occurred. (We recorded all of the talks, so the audio will ultimately be posted online as well.)

The presentations in the symposium covered a wide geographical and chronological range and complemented each other well, largely as a result of the skilled planning of Richard Dunn and Margaret Schotte. The ways in which they intersected highlighted how pan-European the early modern 'search for the longitude' and related activities were, something which I and Richard and Katy Barrett and other speakers specifically addressed. There was much communication, collaboration, and also disagreement between individual and institutional longitude actors across Europe, Russia, and their current and former colonies - even during times of international war.

The first session, 'State interests', was chaired by our Rebekah Higgitt and gotten off to a good start by Richard. Richard discussed 'Clocks and courts: Anglo-Dutch-French relations in seventeenth-century attempts to perfect the marine timekeeper'. This was the very interesting story of the collaboration and ensuing rights disagreement between the Scottish Fellows of the Royal Society Alexander Bruce and Robert Moray and the Dutchman Christiaan Huygens over an experimental triangular sea clock. At least two examples of this clock still exist, one of which will appear in the major longitude exhibition designed by Richard and Becky, opening at the National Maritime Museum next year. It was interesting how, when the three men fell out over who owned the rights to the design, the Royal Society sided with Bruce by essentially saying that Huygens had given up his rights to future permutations of the pendulum which he had designed by putting it out into the public sphere. Similar issues would later arise with respect to technologies such as the achromatic lens and John Harrison's marine timekeepers.

Our new friend Wolfgang Köberer, lawyer by day and historian of navigation by night, next provided a very useful overview of early longitude schemes and publications in the German states. This was rich in detail and extended from the Classical commentaries and first navigational publications of the 1500s to name individuals such as Raphael Levi and especially Tobias Mayer during the 1700s (both of whom popped up in my own talk). I found it interesting that the first German navigational manual, published in 1578, was by a British privateer named James Alday who was working for the Danish King. Alday promised a second book on longitude but passed away before producing it. Wolfgang also interestingly commented, in response to a question by Frank James, that it was indeed likely there was such a strong eighteenth-century connection between German and British longitude efforts because of their joint Hanoverian rule.

The knowledegable Danielle Fauque of Université Paris-Sud 11 next discussed 'French work on longitude methods in the mid-eighteenth century'. Danielle first outlined the early eighteenth-century French longitude prizes, work by individuals including Lacaille and Lalande, and the institutions to which French projectors sent their proposals. She then gave us a rich wealth of information and original documents on voyages of the 1760's and 1770's on which the timekeepers of Le Roy and Berthoud and the lunar distance method were tested and compared. I found it interesting that for the 1767 voyage of the Aurore, the wealthy academician the Marquis de Courtanvaux actually had a frigate specially built for the clock trials!

Finally, Jacob Orrje of Uppsala University rounded out the first session with a fascinating talk on 'State interest and transnational circulation: following a Swedish astronomer into the spaces of English longitude research, 1759-60'. Jacob showed how the travel diary of the Swedish astronomer Bengt Ferrner, a professor at the naval academy of Karlskrona who visited England in 1759-1760, again reflected the intersections of longitude actors from across early modern Europe. This was true even in the midst of conflicts like the Seven Years' War! Ferrner's connection with the Swedish community in London and with related individuals such as the clockmaker John Ellicott opened doors for him to visit individual and institutional longitude and scientific luminaries including the Astronomer Royal Nevil Maskelyne at Greenwich, the Royal Society and its Fellows, and key clockmakers and scientific instrument makers such as John Harrison and Jeremiah Sisson. At Sisson's shop, the astronomer even got to sit in Christopher Irwin's marine chair - which did not much impress him. He also concluded that Dollond, of achromatic lens fame, did not know much about mathematics.

Continue on to Part Two to read about the second and third sessions and concluding commentary of the symposium.