In Europe meridian 8°24’E begins by marking the west coast of Sardinia. the following are the geographical coordinates of several of the important capes on this coast:
According to Pliny (III, 7, 84) the western coast of Sardinia has a length of 175 Roman miles, or 2 1/3° of latitude, and is at the distance of 200 Roman miles, or 2 2/3° of latitude from Africa, that is, from the parallel that divides Europe from Africa. This description fits perfectly the scheme I have presented, except for the detail that the western coast of Sardinia is given a length of 2°20’ instead of 2°50’. This figure may merely be the result of a reckoning in round figures. Pliny reckoned Sardinia as beginning at 36°12’N + 2°40’ = 38°52’N; Capo Spartivento is at 38°53’N. He reckoned Sardinia as ending at 38°52’N + 2°20’ = 41°12’N, which is 5’ north of Punta Caprara. This rounding of the figure was inevitable once the reckoning was started from latitude 36°12’N, instead of latitude 36°06’N, since Sardinia was understood as ending 5°00’ north of the basic parallel.
Nevertheless Pliny, or his source, had a correct datum for the latitude of Punta Caprara, since Pliny states that the straits between Sardinia and Corsica, the Bacchedi Bonifacio, have a width of almost 8 miles and that the eastern coast of Sardinia, which comes closer to Corsica, has a length of 188 miles, that is, extends 13 miles further north than the basic western coast. This means that there were 20 miles or 16’ of latitude between the southern limit of Corsica and Punta Caprara. This puts Punta Caprara at 46°22’N - 0°16’ = 46°06’N. The exact position of Punta Caprara is 46°07’N.
The southern limit of the west coast of Sardinia was set at Capo Spartivento (38°53’N, 8°51’E) and the northern limit was set at Punta Caprara (41°08’N, 8°20’E). On the basis of these data it was assumed that Sardinia extends 5°00’ north of the parallel that divides Europe from Africa, which is parallel 36°00’N, at times reckoned as 36°06’N or 36°12’N. But it was also reckoned that Sardinia begins at 2°50’ north of the basic parallel, whereas ideally Sardinia should have started on this parallel.
Ptolemy misunderstood it this information, and placed it at the ideal latitude. The latter places the important capes of the western coast of Sardinia along his meridian 30° P, which corresponds to our meridian 8°24’E. But he misinterpreted the data relating to latitude: for him the western coast of Sardinia extends from latitude 36°N (Pacheion Promontory 36°N 30°40’ P) to a point 2°45’ to the north (Gorditanum Promontory 38°45’N, 29°50’P). In matter of latitude, Ptolemy placed the northern limit of Sardinia where he should have placed its southern limit; he eliminated the interval between Sardinia and parallel 36°00’N or 36°12’N. His source of information, however, had calculated correctly the position of Capo Spartimento as 36°06’N + 2 3/4° and of Punta Caprara as 36°06’N + 5° It is conceivable that the error of Ptolemy is reflected in his toponomy. The southern limit of Sardinia is called by him Pacheion Promontory, which means Fat Promontory, in Greek, whereas the northern limit is called Gorditanum Promontory. Now, gordito in Spanish, which is closely related to the Romance dialects of Sardinia, means fat.
The latitude of the northern point of Sardinia was linked with the displacement of 5°00’ to the north of all Africa west of meridian 10°04’E (conceived as an auxiliary of meridian 8°24’E). The ancients felt that there was a gap in the Bight of Biafra, by which the mouth of the Niger and the southern coast of West Africa are at latitude 5°00’N instead of being at the Equator. This is the reason why Plato speaks of the sunken territory of Atlantis extending from the Equator to latitude 5°00’N. Correspondingly the northern coast of West Africa, west of meridian 10°04’E, was conceived as being pushed 5°00’ to the north, instead of being on the line of the basis of the Delta of Egypt, that is, ending at latitude 31°06’N or 31°12’N. It was felt that this displacement of 5°00’ to the north was reflected in the northern limit of Sardinia.
Since the ancients were always searching for symmetries in physical features of the Earth, they may have conceived that Sardinia, by extending to a point 5°00’ north along the southern European end of meridian 8°24’E, extended as much as Norway, conceived as an island, extended south from the extreme northern limit of the same meridian. The southern limit of Norway at Lindesnes (57°59’N, 7°03’E) is 5°00’ south of the extreme northern limit of Europe and of meridian 8°24’E, that is, the point Thule on the extreme parallel 63°00’N.
The gap between the southern limit of Sardinia and the parallel that delimits Europe to the south was linked with the fundamental shift in European geography from its ideal model. The course of the river Istros or Danube was conceived as marking the middle line between the Pole and the Equator (45°00’N) and also the middle line of the European land mass. But whereas the Istros had its mouth at latitude 45°12’N and continued at that latitude as far as Belgrade, beyond that point it was deflected to the north reaching parallel 8°24’E at the sources of the Danube, which are the point Pyrene at latitude 47°54’N. Hence, it was understood that all Europe was dragged to the north by 2°50’ along meridian 8°24’.
This push to the north determined the position of the southern limit of Sardinia, which is 2°50’ north of parallel 36°00’N, as I have already explained.
The land mass of Europe was conceived as extending 9° south and 9° north of the meridian of the Istros, as Herodotus reports. This means that the coast of Germany on the Baltic Sea was conceived as running along parallel 54°00’N or 54°12’N. But the pushing of Europe to the north along meridian 8°24’E, identified with the western coast of the peninsula of Jutland, was conceived as having created this peninsula that protrudes by 2°50’ beyond the line of the northern coast of Germany. The extreme northern point of the peninsula of Jutland is at Skagen (57°43’N, 10°36’E).
Apparently the push to the north along meridian 8°24’E was understood as explaining the northwards curvature of the coast of Liguria in Italy. As I shall explain, it was understood that without this push of 2°50’ to the north the coast of Liguria would have coincided with the southern limit of Corsica, and in turn Luzern, being conceived as the northern shore of the Lake of Four Cantons, would have been where the Ligurian coast actually is.
It must be remembered that all that I have mentioned was taken as a convenient mnemonic formula, not as an expression of actual physical occurrences. It was mythos.