I can&rsquot blame the algorithm though. It&rsquos only dutifully tracked my obsession for this fortnight&mdashthe David Rumsey Historical Map Collection. Ever since I heard of this digitised archive of over 92,000 maps, I could focus on nothing else. Starting from the 16th century to the present, the collection (which, including offline stores, holds more than 150,000 maps) is a hefty catalogue of atlases, maritime charts, celestial maps, pocket charts, globes, vintage advertisements...I can&rsquot even begin to cover its scope. The collection was started over 30 years ago by map aficionado David Rumsey, who currently heads Cartography Associates.