| |
|
|
|
The challenge of Africa: from1788
|
The ability of European ships to sail anywhere on the oceans of the world - culminating in the great voyages of Captain Cook in 1768-79 - means that by the end of the 18th century the coast lines of the continents are familiar. So, from many centuries of to and fro, are the interior regions of Europe and Asia.
The interiors of the other three continents remain largely a mystery. North America will soon have heroic tales of exploration (particularly that of Lewis and Clark in 1804-6) and Australia's fearsome outback will claim tragic victims (such as Burke and Wills). But it is the ancient continent of Africa which now most fires the imagination of explorers, particularly in Britain.
|
|
|
|
The mouths of Africa's great rivers - the Nile, the Niger, the Congo, the Zambezi - are familiar to European traders. And there are reliable reports of great stretches of inland river. But no one has any idea how it all joins up. Where do the inland rivers reach the sea? Where do the estuary waters come from? These questions tantalize explorers from the late 18th century to the heady days of Livingstone, Burton and Speke.
By the time the discoveries of these intrepid adventurers have been passed to the cartographers, the maps of the world have few blank areas left. Improved techniques of surveying will refine the detail. But geography, in a schoolroom sense, is complete by the late 19th century.
|
|
|
|
|
Improvements: 18th - 20th century
|
|
Once the basic information about the world's landscape is broadly known, improvements in mapmaking become those of greater accuracy, clarity and detail.
A strong impulse towards better surveying and mapmaking comes from the demands of the military. Britain's national cartographic agency admits as much in its title. It is established in 1791 as the Ordnance Survey ('ordnance' being an old-fashioned word for artillery). With a threat of invasion from France during the 1790s, it is not surprising that detailed maps of Kent are the first to be printed.
|
|
|
|
|
Advances in surveying make it possible to calculate with accuracy the height of mountains and later even the depth of oceans. Places of the same altitude can be plotted, and recorded in the form of contour lines. By the late 20th century satellites add a new dimension. Powerful lenses in orbit above the earth record the tiniest details on the planet's surface, plotting even the changing patterns of weather or vegetation.
Improvements in colour printing make it increasingly possible to publish this wealth of information in complex form. And digital technology brings an added flexibility in the use of maps on computer screens.
|
|
|
|