A very fine detailed large scale map of the county of Northumberland with an inset plan of Newcastle lower right showing the high level bridge and the swing bridge. The key helps to identify not just the railway line but also those for mining purposes. The roads are detailed down to ‘Farm Roads and Footpaths’. The partnership between Mawson, Swan and Morgan began in 1878. An interesting anecdote is that Swan was granted the patent for Bromide paper in 1879 for photographic use, the type most commonly used to this day. In 1860 Swan devised a primitive electric light bulb which did not work long due to the difficulties of a poor vacuum. It was his basic design that Thomas Edison used twenty years later!