Book 2
4.2
I will not inquire, says Polybius, whether the statement concerning the 3000 stadia is correct or not, but 7000 stadia is not the correct measure [from the Strait of Messina to the Pillars of Hercules], whether taken along the sea-shore, or right across the sea. The coast closely resembles an obtuse angle, one side reaching to the Strait of Sicily, the other to the Pillars, the vertex being Narbonne. Now let a triangle be constructed, having for its base a right line drawn through the sea, and its sides forming the aforementioned angle. The side reaching from the Strait of Sicily to Narbonne is above 11,200 stadia, while the other is below 8000. Now the greatest distance from Europe to Libya, across the Tyrrhenian Sea,That part of the Mediterranean which lies on the coast of Italy, from the mouth of the Arno to Naples. is not above 3000 stadia, and across the Sea of SardiniaThe sea which washes the western coast of Sardinia. it is less still. But supposing that it too is 3000 stadia add to this 2000 stadia, the depth of the bay at Narbonne as a perpendicular from the vertex to the base of the obtuse-angled triangle. It will, then, be clear even to the geometrical powers of a child, that the entire coast from the Strait of Sicily to the Pillars, does not exceed by more than 500 stadia the right line drawn across the sea; adding to these the 3000 stadia from the Peloponnesus to the Strait of Sicily, the whole taken together will give a straight lineViz. from the Peloponnesus to the Pillars of Hercules. above double the length assigned by Dicaearchus; and, according to his system, you must add in addition to these the stadia at the recess of the Adriatic.
