Recently, I found an interesting book on the longitude problem by Dava Sobel. The book entitled 'Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time' is the dramatic human story of an epic scientific quest.
The 'longitude problem' was the serious dilemma of the eighteenth century. Lacking the ability to measure longitude, sailors and explorers had literally been lost at sea. Dava Sobel's book shows how this problem was solved. She presents the figure of John Harrison, self-taught Yorkshire clockmaker, and his forty-year obsession with building the perfect timekeeper which could help to calculate the longitude on the sea.
The book gave me some hints on where to look for navigation instruments used in the past.
Harrison's chronometers as well as many other instruments may be found in the National Maritime Museum in London.
http://www.nmm.ac.uk/
The Science Museum in London also has a Surveying section. Unfortunately, it will be closed till summer time.
http://www.sciencemuseum.org.uk/
