From Alex: An Introduction to the history of maps.

What do we know about maps? How did we arrive at the system we now use to describe the landscape and the buildings and installations that it contains?  Alex has put together this useful bit of information about the history and language of mapping. 

Interpreting maps

Maps

A map is a symbolic visual depiction, illustrating the relationship between various objects or locations.

Usually maps are geographical,  geological or astronomical, but there are even maps of the brain.

 

People have been making maps for thousands of years & they may not look like the kind of maps we imagine when we think of maps.

The earliest known maps are of the stars, not the earth. Dots dating to 16,500 BC found on the walls of the Lascaux caves map out part of the night sky.

.Herodotus wrote a book called HISTORIES in 5bc. He divided the world into three continents Asia, Africa & Europe & he described all the peoples in the world he had heard of & the location of their lands relative to each other.

This is great for exploring the ancient world in your imagination, But not very good for getting around in the physical world.

 Maps, art & maths

Maps combine Art & maths, often very precise measurements of direction, length & height must be made.

In the past the tools for mapping were very easy to find but hard to use, Knowing the rising positions of stars can help you get accurate directions BUT the stars of the horizon vary between different times of the year & different countries & what if its cloudy?  So it was a very special skill.

Our star (the sun) will help us find east & west as it travels its daily course & it will also let us know what time it is.

These two facts Time & Direction will let you work out roughly how far you have travelled & to where.

 Old maps used many different systems of alignment. Old Japanese maps had the city of Edo at the top & aligning maps to the city of Jerusalem a popular choice for Christian nations.   

 Around 206bc in China, a device was developed which made navigation more accurate, called the Sinan, meaning south governor. This device became known as the Compass. A compass has a magnetised needle which, always tries to point towards magnetic north. Magnetic north is the point where the Earth magnetic field focuses directly downwards & this is very handily near the north pole (northern polar axis). With this invention there was always one direction you could always find day or night, in any weather & travelling far over the ocean & deserts became safer. Soon aligning maps with north to the top became the normal.

 Another way to orientate a map is by using the sun and an analogue wrist watch. If a person points the hour hand (smaller hand) on his or her watch towards the sun, south will always be half way between 12 and the hour hand. North will be in the exactly opposite direction of south.

  .The oldest known world map is on a clay tablet made by the Babylonian peoples of ancient Iraq in 600bc. Although its a symbolic map of how they imagined the world to be & doesn’t include countries they didn’t like !

 Ptolemy was a Roman Geographer who 150ad. He wrote famous books about Cartography or map making. The Geographia, a book about how to map the earth  & The Almagest, a book about the stars & planets. These books combined to set out his grand scheme.

He divided the world map up by grid & assigned a set of coordinates to each place or geographic feature .

This proved a very popular system & was still used in the 15th-century.

The word “Map” comes from the Medieval Latin name, mappa mundi, meaning cloth world, because some maps were painted on scrolls of cloth to make them easy to roll up & transport.

.Gerardus Mercator was a Flemish mapmaker who in 1569 realised that if you try to fit a squared grid map around a spherical earth, it stretches out of shape. So he developed a system of geometry to correct the distortion.

This was called the Mercator projection & was so far ahead of its time it took many years before people actually had the tools to measure distances that accurately, although it is a very widely used system today.

   

 

  Map symbols.

.Many different sets of symbols have been used as a kind of short hand to describe places of interest on a map.  People who create maps (cartographers) always try to draw symbols which resemble the feature that they are representing, So a camping ground may be a simple picture of a triangular tent or a old castle may be a tiny drawing of a castle.

The maps of the Australians Aborigines use a ancient set of traditional symbols called pictogram. Many of these look like what they depict. Some are harder to work out.

 Our Ordinance survey maps also use a set of traditional pictograms & often the bigger they are the more important the location they indicate.

 It has become a convention for certain colours to represent certain features. Blue for water, including lakes and rivers. Vegetation is often featured as green & sands in yellows.

 

Maps frequently have a special text box called the Legend, this has an explanation of what all the different symbols used on the map mean.

"Terra incognita or terra ignota". The Latin term for unknown lands has been used since Ptolemy to label areas of the map that have not been explored. English maps use the label Parts Unknown.

"Hic Sunt Dracones". The Latin for here is dragons wasn’t really used on maps very often & is thought to relate to the Komodo dragons of the Indonesian isles.

There are certainly some odd creatures drawn on maps. Arabic maps frequently drew there astrological monsters on maps as a aide to navigation.

Oddly "Hic Sunt Leones", (here is lions), was a very popular way of saying "we don't know what is here."

                                                    Ariel maps & texture.

Now we can use satellites on the edge of space to map the word in fine detail using remote sensing.

Different forms of Satellite imaging clearly show the different land usages over large areas, Satellite images have many applications. Meteorology ( the study of weather), geology, Cartography, conservation and , sadly, warfare are some of the uses.

In 1972 the USA started the largest program for  gathering imagery of Earth from space, called Land-sat Program.

GPS The Global Positioning System became available in 1995,  it is a Satellite Navigation system that provides location and time information in all weather conditions, anywhere on Earth.

         Different types of sensor record different information.

Some common passive sensors that satellite's use, are infra-red & radiometry. These are often given artificial colour schemes to assist in the interpretation of what we see.

 Another common passive sensor is Photography.

Photographed from space,the  earth becomes a mosaic of textures. the regular shapes of housing developments, contrast with the patchworks of fields & the smoky intrusion of the sea.

Alex.