Слайд 4
The Portolan Grid
Equator and 45N are quite accurate
Map
ends just below 45S
Intermediate Roses Might Represent Tropics (23.5
N or S) or 1/8 of a Hemisphere (22.5 N or S)
Слайд 5
The Portolan Grid
Radiating Lines are Compass Bearings
Meridians and
Parallels are perpendicular
This is a Cylindrical Map Projection
Слайд 6
Quality of Cartography
Europe and Africa
Coasts Pretty Good
Rivers Inaccurate
Brazil:
Recognizable
North America and South of Brazil: Very Poor
Слайд 7
Interpreting Ancient Maps
Any Ancient Map is Only as
Good as Its Depiction of Well Explored Areas
Things of
Practical Use to Mariners (Capes and Islands) Often Exaggerated
Latitude is the Most Likely Parameter to be Accurate; Longitude Largely Guesswork
Imaginary Features Often Incorporated and Gaps Filled In
Слайд 9
The Orontius Finaeus Map, 1531
Слайд 10
Antarctica?
http://www.goldenageproject.org.uk/112antarctica.php
Слайд 15
A Vicious Circle
Without Accurate Navigation, Accurate Maps Weren’t
Necessary
Maps Were Largely Schematic
Without Accurate Maps, there was no
Point in Trying to Navigate Precisely
Coastal Charts, on the Other Hand, Were Valuable
Even Into Modern Times, Many Questioned the Need for Accurate Mapping
Слайд 16
What’s Missing?
The Pacific Ocean
Isthmus of Panama
Drake Passage
Deep Water:
Was Never Dry Land
No Evidence of Antarctic Ice Connection
Any
Indisputable Feature of Antarctica
Слайд 17
Arm-Waving Looks Persuasive
Azimuthal Equidistant Projection Centered on Cairo
Слайд 19
Azimuthal Equidistant Projection Centered on 0,0
Слайд 21
Cylindrical Equidistant Projection