In the days when it was essential for marine navigators to be able to get a good visual fix on stars and other astronomical objects, many inventors tried to find ways of creating a ‘Marine Chair’ which would stay still while the ship rolled about in the middle of the ocean. Various national governments offered generous prizes for coming up with an invention which worked.
The illustration shows one of the first attempts – which unfortunately didn’t perform as well as was hoped. Le Cosmolabe by Jacques Besson, published in Paris in 1587. As professor Martin J Murphy PhD FAAPM from the Department of Radiation Oncology at Virginia Commonwealth University, US explains :
“Similar devices were proposed later by Galileo, Neville Maskelyne, and others as a means of making astronomical measurements for the determination of longitude at sea. (They didn’t work.) “
For another short history of the not-so-successful development of marine chairs, see this essay from Dr Alexi Baker who was a postdoctoral fellow at CRASSH, University of Cambridge, UK, and is now collections manager at the Division of the History of Science and Technology, Yale Peabody Museum, Connecticut, US.
BONUS ASSIGNMENT [optional] Why didn’t marine chairs work?