pdf 1 - exhibitions international

Fig. 2: Soria E Terra Sancta Nova Tabvla from
La Geographia... by Giacomo Gastaldi, published
by Giovanni Battista Pedrezano, Venice
1548; 130 x 170 mm
[24] [25]
Classical scripts including Ptolemy’s books at the end of the 14th century
when a delegation of Byzantine scholars visited Venice and Florence. For the
Florentines this was a revelation. They were so impressed that several decided
to learn Greek and translate them. Jacopo Angeli da Scarperia with the help of
his teacher Manuel Chrysoloras, translated the Cosmographia into Latin during
the years 1400–1407 making it available to the West for the first time in
manuscript form.
GeoGrAphicAl knowledGe At the time of ptolemy
Ptolemy’s concept that the earth was a perfect sphere was based on the teachings
of Pythagoras in the 6th century Bc and the proofs provided by Aristotle
(384–322). He accepted the calculation of the earth’s circumference by Poseidonius
of Apameia (130–52 Bc) of 18,000 miles (50 miles to an arc of 1 degree)
rather than that of Eratosthenes of Cyrene of 25,200 miles (70 miles to an arc
of 1 degree). This made the Earth circumference 18% smaller than the true
size. His concept of the sun and planets in orderly orbits around the stationary
earth at the centre of the universe with the stars fixed
on an outer celestial sphere also rotating round the earth
was the most popular at the time, while rejecting the heliocentric
hypothesis of Aristarchus of Samos (310–230 Bc).
The latitude of a locality was the angle of inclination
from the equator and was between 00 and 900 depending
on the distance from the equator. It could be determined
from several measurements such as (a) the elevation of the
north celestial pole above the horizon, (b) the ratio of a vertical
stick (gnomon) to its shadow on the longest and shortest
days of the year or (c) the ratio of the longest day of the
year to the shortest, or even the length of the longest day.
Thus, Ptolemy gives latitude as hours of sunlight.
Longitude was measured eastward starting at the Fortunate (Canary)
islands and Ptolemy drew his meridians at “intervals of a third of an equinoctial
hour” i.e. at 50 intervals.
“The Zodiacal circle”, the ecliptic, was recognised as the circle tilted at
an angle of 240 traversed by the sun at a rate of just under a degree a day opposite
to the rotation of the stars. The most northerly point of the ecliptic defined
the Tropic of Cancer and the most southerly the Tropic of Capricorn.
Tow further circles were recognised, the Arctic and Antarctic where the
longest day of the year just reached 24 hours.
Although the division of the circle to 3600 dates to Babylonian times
and was used by the Greek astronomers and mathematicians,
Ptolemy was the first to apply it in the use of terrestrial coordinates
for specifying geographic positions.
The habitable world of Ptolemy, the oikoumene, occupied
one quarter of the earth, from just south of the equator to the
64½ degrees north of the equator, and from the fortunate islands
00 longitude to the end of the “Silk country” 1800 longitude.
Thus, the width of Europe and Asia were exaggerated by 30%.
Ptolemy believed that there was a southern land counterbalancing
the land north of the equator so that the Indian Ocean was
shown as a closed sea, but this land south of the equator was too
hot to sustain human life. On the question whether the land on
the other side of the earth was inhabited Ptolemy kept an open mind. The
oikoumene was divided in three continents, Europe, Libye (Africa) and Asia.
In the Geographia, Ptolemy states that to draw the world map on a globe
is a method of ensuring correct representation of distances, but argues that
globes are usually too small to show detail and he describes how to make
projections on a flat surface. He gives detailed instructions how to make three
different projections. His first projection is a conical one. In this projection
east-west distances are portrayed in correct proportionality to north-south
distances only along the parallel of Rhodes. His second projection is a pseudoconical
one that preserves the ratio of the total latitudinal dimension to the
total longitudinal dimension for all parallels. A third spherical projection is a
modification of the second, but has not been used in any of the manuscript or
printed Ptolemaic atlases. In addition to the world map, Ptolemaic atlases
contain 26 regional maps with equidistant meridians and parallels: 10 for
MAPPING CYPRUS EUROPEAN CARTOGRAPHERS AND CYPRUS
Fig. 3: Asiae IIII Tab: From Tabvlae Goographicae
Cl. Ptolomei... edited by Gerard
Mercator, and printed by Godefrid von
Kempen, Cologne, 1578; 345 x 465 mm