Navigation and knowledge
The Roman Empire included parts of Africa; this copy of a map by Claudius Ptolemy (c.100-170AD), the Greco-Egyptian astronomer and cartographer, shows how they saw the continent at the time. This map is actually from Geographia published by Sebastian Munster of Basle in 1540.
An astrolabe is an extremely versatile observational and mathematical instrument. This example, made by the famous astrolabe maker, 'Abd al-A'imma, like most Islamic examples, includes a qibla indicator (the top right corner). This graph indicates the direction of Mecca for different cities on any day.
The maker of this astrolabe was from a family of astrolabe makers from Mughal Lahore. During this period the Islamic world covered much of Africa, Asia and the Middle East and knowledge travelled easily between the different countries. This astrolabe has 5 plates, showing the positions of stars for eight different latitudes.
Map of Africa, 1554
By the 16th century Europeans were beginning to establish themselves in Africa. This map by the Genoese cartographer Battista Agnese (1514-1564), then working in Venice, dates from 1554, over 100 years after Europeans had settled in Africa. It shows how they then viewed the continent.
This globe only shows co-ordinates. This type of globe could be used for showing the position of the Sun at different times of year for different latitudes. It could also be used to make very detailed calculations, in conjunction with measurements of the Sun's altitude made with a quadrant, for time of day.
Celestial Globe (Islamic), showing stars only, c.1615AD
This globe shows and labels 14 stars, but no constellations. This globe could be used to make all the same calculations as the globe that shows no stars. It could also be used for additional calculations. One such calculation was to use the stars to find the qibla, or direction of Mecca for prayer, for any given town.
Celestial Globe (Islamic), showing stars & constellations, c.1549AD
The constellations illustrated on these globes come from the Roman Ptolemy's star chart, who in turn was recording the constellations invented by the ancient Greeks. The star names, which in many cases are the same as those used around the world today, are Arabic
Celestial Globe, John Senex, c.1750
This globe shows the standard 48 Ptolemaic constellations, those known since antiquity and visible from the Northern hemisphere. In addition to these are 12 constellations of the Southern hemisphere. These constellations were introduced by Petrus Plancius, cartographer for the Dutch East India Company and bear little resemblance to those used by local people.
Chinese Planisphere, 1780
This is called Huangdao zongxingtu meaning 'the celestial map divided according to the ecliptic'. The southern hemisphere lies on the left, the northern hemisphere to the right. Winter is at the top of both hemispheres, autumn lies in the middle, summer is situated at the bottom, while spring is at the outside edges.
Quadrant, Indo-Persian, probably 17th century
A quadrant is an instrument for measuring the angle above the horizon of a celestial object. Both sides of this example are engraved as a prophatius, or astrolabic, quadrant. This enables it to be used to determine the time. This example is also engraved for two latitudes allowing it to be used in two separate locations.
This type of sundial was made in Europe for the Islamic market. Besides the use of Arabic script, the other important difference is that it shows the direction of Mecca, as well as the time. Sometimes such dials also include a reminder of prayer times.