The complete demolition of the Eratosthenes myth: new radical chronology comes to the rescue.

http://www.ilya.it/chrono/pages/erdmessungen.htmUwe Topper, one of the best European new chronologists:

"In school we learned that Eratosthenes (276-194 B.C.), director of the great library at Alexandria, was the first to determine the size of the earth. Yet his alleged method does not convince me at all.

The following procedure is described: He assumed that Alexandria and Syene (now Assuan on the Nile before the first cataract) are situated on the same meridian and are exactly 5000 stades distant from each other. The latitudinal difference is given as 7°12' which is accurate. But these towns don't lie on the same meridian - Alexandria is 30° eastern longitude and Syene is 33°. The difference of 3° amounts to more than 300 km. We don't know how Eratosthenes determined these towns are 5000 stades distant (which is close enough). From these data Eratosthenes calculated the circumference of our planet to be 252,000 stades, which is astonishingly correct. The stade used in Egypt is 157,5 m, and thus the earth's circumference 39,690 km which is fairly correct (today a bit more than 40,000). It means roundabout 110 km distance between two parallels (today 111 km).

The latitudinal difference between Alexandria and Syene, 7°12', is exactly a 50th part of the whole circumference. If this had been applied correctly in the calculation, the circumference would have come to 250,000 stades, or 2000 stades short of what Eratosthenes assumed. This suggests he knew the outcome in advance and only looked for measures that let to the right result.

My doubts are reinforced if we consider the length of the stade: 40,000 stades make the radius of the earth, and 1° of the earth's circumference equals exactly 700 stades. Thus I conclude the stade is a measure deducted from the size of the earth. If Eratosthenes applied it to measure and calculate the earth, he used the knowledge that people had used before him. And he had to twist his mathematical elaboration a bit to arrive at the same result.

Then came Eratosthenes. His books are not preserved, only some contents of the "Book of Dimensions" are quoted in Galen, and other parts mentioned in the "Geographica" of Strabo. Although Eratosthenes divides the circumference into 60 parts, he does not use this calculation, but transforms his measures into stades (see also Harley and Woodward, vol.I, p.155). One 60th of the circumference amounts to exactly 4200 stades, 42 being the typical sacred number of the Egyptians. The tropic given by Eratosthenes is situated 16,800 stades from the equator, that is 4/60th of the circle, which we would today describe as 24° northern latitude.

In order to get more exact results, Eratosthenes applied two more manipulations.

First, a group of royal geodesists measured the distance from Syene to Meroe in the Sudan (today: Dar Shendy on the Nile), which came to 5000 stades. In this case the longitudinal difference is only 2°, but it is not negligible. And how could they really measure this great distance (about 800 km) over very rough mountainous surface? Only trigonometry would have served the job, but its use is denied by Miller (p.24). He talks about measuring by steps or with a rod or a rope, always reducing the outcome to the meridian. Let us assume that this might be probable. This suggests Syene is the center of Egyptian geodetics.

The third improvement need not be taken seriously: Sailors told him that the distance between Rhodes and Alexandria is about 4000 to 5000 stades. That was not an improvement at all. We know that it is nearly impossible to determine the distance a ship has sailed. Eratosthenes neglected the longitudinal difference of 2° and probably used measurements of latitude when he implied a distance of 3750 stades, as Miller says (p.27). Posidonius, who died about 150 years later, chose 4000 stades and arrived at a similarly exact result.

Again, this tells me the result was there first, and the way of obtaining it was a pure guess.

According to Miller (p.16) recent scholars take this view. They speak of Eratosthenes as "unconsciously" arriving at his results, or borrowing them from another learned culture.

For me the question remains: where did Eratosthenes get his knowledge? That he himself was not learned is highlighted by other data given in his texts (Miller p.5): the diameter of the sun is three times that of the earth, its distance is 51 diameters of the earth, and the moon is 19,5 earth-radii away. All figures are far wrong.

So if he could not estimate himself, not even nearly, how did he arrive at an exact result for the earth's circumference?

The problem of the incorrect data used by Eratosthenes, especially the 3° difference in longitude, is brushed aside by Miller's remarks (p.6 and p.25), that they are corrected by giving the latitudinal difference between Alexandria and Syene as 7° 1/7 . This is not said in the Greek text, but only surmised by Miller defending Eratosthenes. Miller says Eratosthenes was able to correct his wrong longitudes by the inexact difference of the latitudes and thus find the real circumference of the earth. Committing two mistakes and arriving at the correct result means that he knew the result in advance."