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.
