In the geographers of the late Roman Republic and early Roman Empire, such as Ptolemy, Scythia stretches eastward from the mouth of the Vistula ; thus Pytheas must have described the Germanic coast of the Baltic sea ; if the statement is true, there are no other possibilities.

The inhabitants or people of Thule are described in most detail by Strabo in his Geographica, having preserved fragments of the account of Pytheas who was an alleged eye-witness in the 4th century BC:

Pytheas of Massilia described a similar expedition in more detail a few centuries later, around 325 BC.

The Greek explorer Pytheas is the first to have written of Thule, doing so in his now lost work, On the Ocean, after his travels between 330 BC and 320 BC.

Another early reference to Amber was Pytheas ( 330 BC ) whose work " On the Ocean " is lost, but was referenced by Pliny.

Most of the ancients, including the first two just mentioned, refer to his work by his name: " Pytheas says ..." Two late writers give titles: the astronomical author Geminus of Rhodes mentions ( ta peri tou Okeanou ), literally " things about the Ocean ", sometimes translated as " Description of the Ocean ", " On the Ocean " or " Ocean ;" Marcianus, the scholiast on Apollonius of Rhodes, mentions a ( periodos gēs ), a " trip around the earth " or ( periplous ), " sail around.

Strabo and Diodorus Siculus ) never saw Pytheas ' work, says Nansen, but they and others read of him in Timaeus.

In discussing the work of Pytheas, Strabo typically uses direct discourse: " Pytheas says ..." In presenting his astronomical observations, he changes to indirect discourse: " Hipparchus says that Pytheas says ..." either because he never read Pytheas ' manuscript ( because it was not available to him ) or in deference to Hipparchus, who appears to have been the first to apply the Babylonian system of representing the sphere of the earth by 360 °.

Pytheas however could not then answer for himself, or protect his own work from loss or alteration, so most of the questions concerning his voyage remain unresolved, to be worked over by every generation.

Fosite has been suggested to be a loan of Greek Poseidon into pre-Proto-Germanic, perhaps via Greeks purchasing amber ( Pytheas is known to have visited the area of Heligoland in search of amber ).

The consensus has been that he probably took his information from Pytheas through Timaeaus.

To get this country south of Britain to conform to Strabo's interpretation of Pytheas, Ptolemy has to rotate Scotland by 90 °.

The association of Pytheas ' observations with drift ice has long been standard in navigational literature, including Bowditch, which begins Chapter 33, Ice Navigation, with Pytheas.

Citing numerous instances of Pytheas apparently being far off the mark on details concening known regions, he says: " however, any man who has told such great falsehoods about the known regions would hardly, I imagine, be able to tell the truth about places that are not known to anybody.

With this tale complete Bacchylides proclaims once again that the actions he has just told will be forever remembered thanks to the muses, leading once again into his praise of Pytheas and his trainer Menander, who shall be remembered for their great victories in the Pan-Hellenic games, even if an envious rival slights them.

It has been suggested that the land called Thule by the Greek merchant Pytheas ( 4th century BC ) was actually Iceland, although it seems highly unlikely considering Pytheas ' description of it as an agricultural country with plenty of milk, honey, and fruit ( possibly the Faroe or Shetland islands ).

Polybius in his Histories ( c. 140 BC ), Book XXXIV, cites Pytheas as one " who has led many people into error by saying that he traversed the whole of Britain on foot, giving the island a circumference of forty thousand stades, and telling us also about Thule, those regions in which there was no longer any proper land nor sea nor air, but a sort of mixture of all three of the consistency of a jellyfish in which one can neither walk nor sail, holding everything together, so to speak.

" But he then doubts this claim, writing that Pytheas has " been found, upon scrutiny, to be an arch falsifier, but the men who have seen Britain and Ierne ( Ireland ) do not mention Thule, though they speak of other islands, small ones, about Britain.

* Pytheas of Massilia, ( 4th century BCE ) On the Ocean ( Περί του Ωκεανού ), has not survived ; only excerpts remain, quoted or paraphrased by later authors, notably in Avienus ' Ora maritima.

O ' Rahilly ( 1946 ) has concluded from this that his description is probably based on data collected in the 4th century BC by the early explorer Pytheas.

Pytheas says that the Gutones, a people of Germany, inhabit the shores of an estuary of the Ocean called Mentonomon, their territory extending a distance of six thousand stadia ; that, at one day's sail from this territory, is the Isle of Abalus, upon the shores of which, amber is thrown up by the waves in spring, it being an excretion of the sea in a concrete form ; as, also, that the inhabitants use this amber by way of fuel, and sell it to their neighbors, the Teutones.

During the last half of the 4th century BC, the time of Pytheas ' voyage, Massaliotes were presumably free to operate as they pleased ; there is, at least, no evidence of conflict with Carthage in any of the sources that touch on the voyage.

Nansen goes on to point out that Pytheas must have stopped to obtain astronomical data ; presumably, the extra time was spent ashore.

Pytheas says that the Gutones, a people of Germany, inhabit the shores of an estuary of the Ocean called Mentonomon, their territory extending a distance of six thousand stadia ; that, at one day's sail from this territory, is the Isle of Abalus, upon the shores of which, amber is thrown up by the waves in spring, it being an excretion of the sea in a concrete form ; as, also, that the inhabitants use this amber by way of fuel, and sell it to their neighbours, the Teutones.

Pytheas claimed to have explored the entire north ; however, he turned back at the mouth of the Vistula, the border with Scythia.

The process continues into modern times ; for example, Pytheas is a key theme in Charles Olson's Maximus Poems.

* The Extraordinary Voyage of Pytheas the Greek: The Man Who Discovered Britain ( 2001 ), Walker & Co ; ISBN 0-8027-1393-9 ( 2002 Penguin ed.

He also wrote on the trade of Carthage, on the geographer Pytheas of Marseille, and two important works on numismatics ( La Numismatique du moyen âge, 2 vols., 1835 ; Etudes numismatiques, 1840 ).

The only surviving pre-Roman account of Scotland originated with the Greek Pytheas of Massalia who circumnavigated the British islands ( which he called Pretaniké ) in 325 BC, but the record of his visit dates from much later.

Pytheas reported only days ' sail.

However, Pytheas only sailed 560 stadia per day for a total of 23800, which in Nansen's view is consistent with 700 stadia per degree.

From these few references, which are the only surviving evidence apart from place name analysis, it would seem that the Balts Pytheas would have encountered were past the Common Balto-Slavic stage, but still spoke one language, which would have been Proto-Baltic.

In whatever mathematical form Pytheas knew the location, he could only have determined when he was there by taking periodic readings of the elevation of the pole ( eksarma tou polou in Strabo and others ).

The astronomic model on which ancient Greek navigation was based, which is still in place today, was already extant in the time of Pytheas, the concept of the degrees only being missing.

Pytheas was a central source of information to later periods, and possibly the only source.

The traveller Pytheas, whose own works are lost, was quoted by later classical authors as calling the people " Pretanoi ", which is cognate with " Britanni " and is apparently Celtic in origin.

Pytheas was quoted as writing that the Britons were renowned wheat farmers.

Earlier Pliny says that a large island of three days ' sail from the Scythian coast called Balcia by Xenophon of Lampsacus is called Basilia by Pytheas.

It is possible that Pliny refers to an island named Basilia (" kingdom " or " royal ") in On the Ocean by Pytheas.

The earliest account of Cornish tin mining was written by Pytheas of Massilia late in the 4th century BC after his circumnavigation of the British Isles.

In this passage, Pytheas states that the " Gutones, a people of Germany ," inhabit the shores of an estuary of at least 6, 000 stadia ( the Baltic Sea ) called Mentonomon, where amber is cast up by the waves.

Diodorus does not mention Pytheas by name.

The last link is supplied by Strabo, who says that an emporium on the island of Corbulo in the mouth of the Loire was associated with the Britain of Pytheas by Polybius.

The early part of Pytheas ' voyage is outlined by statements of Eratosthenes that Strabo says are false because taken from Pytheas.

" The word epelthein, at root " come upon ", does not mean by any specific method, and Pytheas does not elaborate.

Pliny gives the circuitus reported by Pytheas as 4875 Roman miles.

Despite Strabo's conviction of a lie, the perimeter said to have been given by Pytheas is not evidence of it.

Manuscript variants however offer a P-alternating with B -, and there is good reason for thinking that the name learned by Pytheas had P -, as in * Pretania or * Pritannia, etc.

" Strabo does not believe it but he explains what Pytheas means by the ends of the world.

Nansenpoints out that according to this statement, Pytheas was there in person and that the 21-and 22-hour days must be the customary statement of latitude by length of longest day.

Pytheas, as related by Hipparchus, probably cited the place in Celtica where he first made land.

The fact that Pytheas lived centuries before the colonization of Iceland and Greenland by European agriculturalists makes them less likely candidates, as Thule was populated and its soil was tilled.