Today's maps rely on overhead surveillance. Wikipedia's history of Cartography lists some key technologies that improved cartography (e.g. telescopes, magnetic compasses, etc.), but doesn't explain in any detail what impact these had on the resulting maps? What are the key technologies that improved cartography, and what impact did they have on mapping? How much more accurate were maps resulting from each of these technological changes? What new capabilities did they introduce to the resulting maps? I also need to know about some of the Famous men in Cartography !
Although Euclid is renowned for his compilation of the axioms and theorems of plane geometry, most if not all of this material had been known for centuries. With these mathematical tools, and the use of strings and simple pedometers and protractors, remarkably accurate maps could be drawn by the ancients for territories that were relatively level and pace-able on foot. Even in land-locked territories, it seems likely that early mapmakers would have realized that the Earth is not flat from the observation that the angles of a triangle increase slowly and progressively beyond the 180 degrees predicted from planar geometry.
With the development of magnetic compasses (to determine North) and sextants and astrolabes (for measuring latitude) larger territories could be mapped. If you look at maps from the early Age of Exploration you will see many maps that in some ways look remarkably accurate, while simultaneously looking distorted to our modern eye. Part of this distortion results from the longitude problem that wasn't fully resolved until the mid-18th century with the final award of the Longitude Prize by the British Admiralty.
In a nutshell, the problem was to determine with accuracy how far east or west one was from a known point (London for British sailors). While the sextant and astrolabe allowed one to determine one's latitude (degrees south or north of equator) with great accuracy, no equivalent method for determining longitude existed at that time. If one was on level land various techniques could be used to estimate a value, but onyly with the invention of the maritime chronometer could longitude be calculated accurately on land and sea.
In the decades after this invention, probably sparked further both by William Smith's first geologic map of England and the Napoleonic Wars, many national governments began comprehensive topological mapping of their domains for military and civilian use. In the early decades of the 19th century, for example, Bavaria's Mad King Ludwig continued the mapping initiative begun by his father, of having all of Bavaria mapped at 1:50,000 scales, and all significant towns and villages mapped at
As trains, planes, and automobiles enabled more people to easily journey further from regions they knew well, road- and trail-maps became increasingly popular and inexpensive, resulting in the great popularity of municipal air-photo maps in the 1960's, with every house marked by a small black rectangle.
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