It was hanging there with majesty, an imposing size, a jaw-dropping blue: our favorite blue piece at the Frieze Art Show 2015 was a gigantic blue map presented by Daniel Crouch Rare Books, a specialist dealer in antique atlases, maps, plans, sea charts and voyages dating from the 15th to the 19th centuries.
G is for Gunsmith
Dr Nevil Maskelyne
Ferries across the Thames
1832 edition of Smith's map of Sussex
Delineating individual sultanates
Jean Dominique Cassini 

