Old globes for young explorers
Ptolemaeus was a Greek scientist whose work dates back two thousand years. He believed that all planets and the sun orbit the Earth. But that is not the case – the Earth and all other plants orbit the sun.
Maps can be drawn in different ways. A Christian map from the Middle Ages shows Jerusalem in the middle as the city is the centre of Christianity. The map does not depict reality. And King Roger II of Sicily ordered a world map from the Arab geographer Al-Idrisi 1,000 years ago. The map depicts Europe, Asia and North Africa as they were only aware of these parts of the world. Cartographers in Europe learnt to draw by looking at the Arab maps.
In days gone by sailors used to share stories of sea monsters. They thought that the same animals on land were also in the sea, but their appearance was slightly different. Consequently there were animals like sea lion, sea elephant, sea cow and sea horse. Piri Reis was an Ottoman admiral from Turkey. In the 16th century he drew lovely maps with trees, cities, boats and ports. He drew the point of the compass north downwards. In Europe it is drawn upwards.
Portolans are maps which only show coasts and ports. The map does not contain anything else from the land. These are maps for sailors and explorers. But also for those who were at home dreaming of faraway places.
It was difficult to find your way when you sailed into an unfamiliar port. A clever way was to use a drawn sketch of the port. Then the captain could compare the sketch with reality and sail to the correct location. The sketches were a drawing of coastal stretches seen from the open sea and served as an aid for navigation, particularly mooring.
It is not very easy to draw a globe on paper. In some way the round surface needs to be flat. It is easier to make a globe which is round, exactly like the real Earth.
The Dutch who made magnificent globes during the 17th century have also drawn their own vessels and strange animals which they sighted in foreign countries in the globes. In Sweden we made our own globes 200 years ago. North America and large parts of Australia were not included as no European had discovered them by then.
When the vessels were out sailing in the open sea, the crew observed the starry sky. The sailors knew which stars to steer by to find their way home. Consequently an officer must be able to recognise many stars.
A long time ago it was discovered that several stars together became a constellation. In order to assist those who look at the sky, constellations are drawn on the celestial globe.