The Dimensions of the Black Sea

Before proceeding further in the analysis of the structure of the geodetic square of Scythia, it is necessary to consider the dimensions of the Black Sea, because these indicate how the geodetic square was linked with the other basic geographic points of the ancient world.

The Black Sea was understood as being included in a rectangle of 10 of longitude and 4 of latitude. But whereas the northern side of the Black Sea could be completely measured as being 10 of longitude, the southern side was wider. This difference was solved by counting the southern side as being in actual length 10 of equatorial longitude which at that latitude correspond to 13½°. This assumes that the degree of longitude is 0.75 of equatorial degree; assuming the earth to be a sphere, this computation is exact for latitude 4124N.

Herodotus refers to these calculations in reporting the dimensions of the Black Sea. He states that the Black Sea has a height of 3300 stadia and a length of 11,100. It is a matter of stadia of 833 to the degree, so that the height is 4 and the length 13½°.

The height, as Herodotus states ( ) is measured (along meridian 3638E) from Sindika to the city of Themiskyra on the river Thermodon. Sindika is the present Taman Peninsula which forms the eastern side of the Strait of Kerch, entrance to the Swamp Maiotis or Sea of Azov. The distance is measured from the very tip which is exactly at 4512N, 3638E and, therefore, is on the base of the geodetic square of Scythia and also 4 to the east of the basic meridian 3238E, the Eastern Axis of Egypt. The terminal on the opposite side of the Black Sea should be the cape presently called Civa Burun (4122N 3638E), but, since this cape is formed by the estuary of the river Thermodon or Yesirlmak that extends for a few miles to the east of the present town of Terme (4112N, 3700E), the line is continued to the beginning of the estuary where there was the city of Themiskyra (near the present town of Carsamba), in order to obtain the exact figure of 400.

The geographical importance of the point Themiskyra is indicated by the fact that the Argonauts stop there before reaching the river Phasis. The line drawn from Sindika to Themiskyra (4 east of the Western Axis of Egypt) corresponds roughly to the eastern end of the Mediterranean (Alexandretta is at 3636N, 3610E). There are versions of the Argonautica in which the return takes place by going from Themiskyra up the Thermodon to the Mediterranean. There can be some uncertainty about the most exact location of the terminal points, but it is obvious that the stretch was measured in a perfect north-south line and extended for 4. We could count from the present Russian town of Taman (4512N 3643E) to the present Turkish town of Carsamba (4113N 3643E) at the middle of the estuary of the ancient Thermodon. Perhaps the line was counted from 4512N 3650E to 4112N 3650E, in agreement with the ancient basic positions. The degree is computed as 833 stadia, so that the figure for the width of the Black Sea should be 3333 stadia; Herodotus rounds it to 3300 stadia or 330,000 orgiai.

Since it is stated that the height of the Black Sea is 3333 stadia and the width is 11,111 (Herodotus rounds the figures to 3300 and 11,100), it can be inferred how the shortening of the degree of longitude was taken into account, since the figures are multiples both of 833 and of 1111. At the latitude of the southern shore of the Black Sea, if a degree of latitude is computed as 1111 stadia, a degree of longitude is 833 stadia, because 833 = 1111 x 0.75 = 1111 cos 4124. This means that when it is stated that the length of the Black Sea is 11,111 stadia, this figure must be interpreted as meaning that the length is 13½° of 833 stadia to the degree, a distance equivalent to 10 equatorial degrees of 1111 stadia to the degree.

Herodotus states that the length of the Black Sea was measured from the mouth of the river Phasis, which is the present Rion in the Republic of Georgia. The reckoning must have started from the area of the present harbor of Poti (4209N 4135E) which is on the northern bank of the Rion. This is the most easterly point of the Black Sea. That this was a point of great geographical importance is indicated by its being the aim of the voyage of the ship Argo, the point where the Golden Fleece was found. Possibly the geographical point was placed at 4212N, 4138E (today at this point there ends a lesser mouth of the Rion), which would be 3 to the south of Sindika and also 5 to the east of the line Sindika-Themiskyra.

The length of 13_ degrees was counted as extending from the mouth of the Phasis along a parallel that almost touches the northernmost point of Asia Minor, the present Ince Burun (4206N 3458E) and just about reaches Igne ada Burun (4152N 2848E), near the present border between Turkey and Bulgaria. The calculation of the length of the Black Sea did not serve geodetic purposes and, hence was a rather approximate one; the length was considered 13½° for the sake of easy reckoning (equal 10 of latitude in actual length).

Apparently Herodotus was befuddled, as were several other Greek writers after him, by the mathematics involved in the calculation of the shortening of the degrees of longitude and confused the length of the Black Sea with another datum, the distance between the mouth of the river Phasis and the entrance to the Bosphoros. This length is described as 11,100 stadia or 1,110,000 orgiai. Herodotus states that the distance from the Bosphoros to the river Phasis is 9 days and 8 nights of navigation.

Rumeli Burun, the cape that closes the Bosphoros to the NW, is at 4114N 2907E; possibly the entrance to the Bosphoros was reckoned as being at 4112N, 2908E. By this reckoning the Black Sea has a length of 12½°. This length is equal to slightly less than 8_ days of navigation by sail; the ancients reckoned 1½° for each day of navigation by sail, so that 8_ days correspond to 12¾. Counting by stadia of 833 to the degree a day of navigation by sail is 1260 stadia. But Herodotus combined the distance of 8_ days of navigation by sail between the river Phasis and the Bosphoros with the distance of 11,100 stadia between the river Phasis and the opposite shore of the Black Sea. Herodotus divided the figure of 11,100 stadia (actually 13½° of latitude) by 8_, and arrived at the conclusion that a day of navigation is 1300 stadia. He explained this figure by assuming that a ship covers 700 stadia during the day and 600 stadia during the night in the summer. This may have been a common practical reckoning, but in geographical calculations it was always assumed that a ship under sails travels 1250 stadia in a full day. He explained the figure of 11,100 stadia as being 9 days and 8 nights of navigation: (9 x 700) + (8 x 600) = 11,100 stadia. The figures of Herodotus certainly contain some distortion since he does not make a distinction between degrees of latitude and degrees of longitude. The distance between Sindika and Themiskyra is 4 or 2 2/3 days of navigation; Herodotus explains it as 3 days or 2 nights of navigation: (3 x 700) + (2 x 600) = 3300 stadia.

The difference of longitude is not counted from the entrance to the Bosphoros, but from Daskyleion, slightly west of Mudanya (4023E) on the Propontis or Sea of Marmara. The reason for reckoning for Daskyleion is that it was the capital of the Persian satrapy called in Persian “Those of the Sea.” This indicates that the planning of the operations against Scythia was entrusted to the satrap of Daskyleion or that the Persian cartographers operated from there. That Daskyleion was the basis of the operation against Scythia appears from Herodotus. His narrative of the campaign ends by mentioning the great praise bestowed by King Darius upon Megabazos, satrap of Daskyleion, for his contribution to the campaign. This may indicate that Herodotus gathered his information at Daskyleion and that possibly it was there that he saw the map of Scythia around which he builds his account. Daskyleion could be easily defended, being surrounded by swamps, had a good communication by road with the rest of the Persian Empire and, at the same time, was as close as possible to both the Bosphoros and the Dardanelles. Since Scythia was mapped taking Daskyleion as a benchmark, it may be inferred that the planning of the operations against Scythia was entrusted to the satrap of Daskyleion. As a closing note, Herodotus relates the following anecdote:


This same Megabazos once made a remark for which the people along the Hellespont have never forgiven him: as he was in Byzantion, on hearing that Chalkedon had been settled seventeen years earlier than that city, he said the people of Chalkedon must have been blind at the time, because, if they had had any eyes, they would never have chosen an inferior site when a much finer one was at hand.

Perhaps this could intimate that Megabazos himself had an interest in geography.

That the meridians were marked as I have indicated is proved also by what follows. After having mentioned the mouth of the Istros or Danube, Herodotus states (II 34) that Egypt extends as far as the mountainous part of Kilikia in Asia Minor and that there are 5 days of march from this to the city of Sinope “going in a straight line.” Since Kilikia is in the southern part of Asia Minor, whereas Sinope, the present Turkish city of Sinup, is near the most northern point of Asia Minor, this is complete nonsense, unless it is understood that Herodotus is speaking of differences of longitude. The mouth of the Danube is on the longitude of the Western Axis of Egypt (2950E), whereas the Eastern Axis of Egypt (3238E) corresponds to the mountainous part of Kilikia, that is, the area of the mountainous group of the Kizildag, which forms the southernmost part of Asia Minor (Anamur Burun, the southernmost point of the coast of Asia Minor, is at 3601N, 3251E). From the mountainous part of Kilikia, assumed to be at 3238E, there are exactly 5 days or 230 to the longitude of Sinope (4201N, 3508E). Sinope was selected as a geodetic point because it is the northernmost city of Asia Minor.

The principles applied in measuring the Black Sea were applied also to the measurement of the Propontis or Sea of Marmara. Herodotus (IV 5) describes the Propontis as a rectangle with a width of 1400 stadia or 236 and a height of 500 stadia, or 36. The SW corner of the rectangle was placed at Gallipoli, 4024N, 2641E; this can be established because Herodotus reports that the length of the Hellespont or Dardanelles is 400 stadia, by which he means 30, always counting by his stadion of 833 to the degree. There are 30 of longitude from Cape Helles at 2611E to Gallipoli. Counting from Gallipoli, the NE corner of the square should be at 4050N 2917E; in fact, this is the position of the Peninsula of Ucburun that can be properly taken as the eastern limit of the Sea of Marmara, since the narrow inlet Izmit Koerfezi may be reasonably excluded from the reckoning.

Concerning the Bosphoros, Herodotus states that its mouth has a width of 4 stadia and that the straits that end at this mouth have a length of 120 stadia. What Herodotus calls the length appears to be measured in longitude as in the case of the Dardanelles; he reckoned 8 or 9 minutes of longitude by the stadion of 833 to the degree. From Istanbul, at 2858E to Rumeli Burun at 2907E there is a difference of 9 of longitude. The width of the Bosphoros at the narrowest point is calculated as 4 stadia or 532 meters; modern tourist guides list it as about 550 meters.

He interprets the 4 or 3300 stadia between Sindika and Themiskyra as 3 days and 2 nights of navigation (2100 + 1200 = 3300).

Since a version of the Argonautica ascribed to Orpheus states that the Tanais or Don, the Phasis, and the Thermodon, originate from the Araxes, the present Araks, which runs through Armenia to the Caspian Sea, there must have been a system of calculations linking the geodetic square with the Caspian Sea. But Herodotus does not mention these calculations. He only mentions the Araxas as emptying into the Caspian Sea, which has a length of 15 days of navigation, or 2230 (I 202). Today the difference of latitude between the two most extreme points of the Caspian Sea (4707N and 3634N) is 1133. Herodotus states that the width of the Caspian Sea is 8 days of navigation or 12. Today the interval between the most westerly point of the Caspian Sea (4643E) and the most easterly point (54, 51E) is 808. These figures can be explained by assuming that to the Caspian there were ascribed dimensions similar to those of the Black Sea, 10 of latitude and 5 of longitude, the 5 being computed as actual length corresponding geographically to 6½° of longitude. Reckoning by stadia of 833 to the degree, the dimensions are 8333 and 4160 stadia. It is possible to reckon the dimensions as 10 by 6½°, but in such a case the latitude must be reckoned by units of 1111 stadia to the degree and the longitude as 833 stadia to the degree. As in the case of the Black Sea, Herodotus was befuddled by this computation and took a day of navigation by oars as the half of 1111 stadia: hence, he said that the length is 15 days (555 x 15 = 8325) and the width is 8 days (555 x 8 = 4440). Whereas texts of geography state that the Caspian Sea may have easily changed its surface in the course of time, the figures prove that its limits in the age of Herodotus were about the same as the present ones.