“Incorporated in a map is the understanding that it is a "snapshot” of an idea, a single picture, a selection of concepts from a constantly changing database of geographic information (Merriam 1996).“

"Old maps provide much information about what was known in times past, as well as the philosophy and cultural basis of the map, which were often much different from modern cartography. Maps are one means by which scientists distribute their ideas and pass them on to future generations (Merriam 1996).”