Editing Pytheas (section)

=== The "circumnavigation" ===
{{stack|[[File:Ptolemy-british-isles.jpg|thumb|350px|A 1490 Italian reconstruction of the map of [[Ptolemy]]. The map is a result of a combination of the lines of roads and of the coasting expeditions during the first century of Roman occupation. One great fault, however, is a lopsided Scotland, which in one hypothesis is the result of Ptolemy using Pytheas' measurements of latitude ([[Pytheas#Pytheas' measurements of latitude|see below]]).<ref>{{cite journal |first=James J. |last=Tierney |title=Ptolemy's Map of Scotland |journal=The Journal of Hellenic Studies |volume=79 |year=1959 |pages=132–148 |doi=10.2307/627926 |jstor=627926|s2cid=163631018 }}</ref>{{pb}}Whether Ptolemy would have had Pytheas' real latitudes at that time is a much debated issue.]]}}
Strabo reported that Pytheas said he "travelled over the whole of Britain that was accessible".<ref name=straboII-4-1>''Geographica'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Strabo/2D*.html Book II.4.1].</ref> Because there are scant first-hand sources available regarding Pytheas's journey, historians have looked at the etymology for clues about the route he took up the north Atlantic.  The word ''epelthein'', at root "come upon", does not imply any specific method, and Pytheas did not elaborate.{{citation needed|date=April 2024}}

Pytheas did use the word "whole" and he stated a ''perimetros'' ("perimeter") for Britain of more than 40,000&nbsp;[[Stadion (unit)|stadia]]. Using Herodotus' standard of {{convert|600|feet|}} for one stadium gives {{convert|4545|miles}}; however, there is no way to tell which standard foot was in effect. The English foot is an approximation. Strabo wanted to discredit Pytheas on the grounds that 40,000&nbsp;stadia is outrageously high and cannot be real.{{citation needed|date=April 2024}}

[[Diodorus Siculus]] gave a similar number:<ref>Book V chapter 21.</ref> 42,500 stadia, about {{convert|4830|miles}}, and explains that it is the perimeter of a triangle around Britain. The consensus has been that he probably took his information from Pytheas through [[Timaeus (historian)|Timaeaus]]. [[Pliny the Elder|Pliny]] gave the ''circuitus'' reported by Pytheas as 4,875&nbsp;[[Mile#Roman|Roman miles]].<ref>''Natural History'' [https://www.perseus.tufts.edu/cgi-bin/ptext?doc=Perseus%3Atext%3A1999.02.0137&layout=&loc=4.30 Book IV Chapter 30 (16.102)].</ref>

The explorer [[Fridtjof Nansen]] explained this apparent fantasy of Pytheas as a mistake of Timaeus.<ref name=nansen51>{{harvnb|Nansen|1911|p=51}}.</ref> Strabo and Diodorus Siculus never saw Pytheas' work, says Nansen, but they and others read of him in Timaeus. Pytheas reported only days' sail. Timaeus converted days to stadia at the rate of 1,000 per day, a standard figure of the times. However, Pytheas only sailed 560&nbsp;stadia per day for a total of 23,800, which in Nansen's view is consistent with 700&nbsp;stadia per degree.{{citation needed|date=April 2024}}

Nansen later states that Pytheas must have stopped to obtain astronomical data. Presumably, the extra time was spent ashore. Using the stadia of Diodorus Siculus, one obtains 42.5&nbsp;days for the time that would be spent in circumnavigating Britain. It may have been a virtual circumnavigation;{{clarify|date=January 2015}} see under Thule below.{{citation needed|date=April 2024}}

The perimeter, according to Nansen based on the 23,800 stadia, was {{convert|2375|miles}}. This number is in the neighborhood of what a triangular perimeter ought to be, but it cannot be verified against anything Pytheas may have said, nor was Diodorus Siculus very precise about the locations of the legs. The "perimeter" is often translated as "coastline", but this translation is misleading. The coastline, following all the bays and inlets, is {{convert|12429|km|mi|order=flip}} (see [[Geography of the United Kingdom#Coastline|Geography of the United Kingdom]]). Pytheas could have travelled any perimeter between that number and Diodorus'. [[Polybius]] added that Pytheas said he traversed the whole of Britain on foot,<ref>Book XXXIV chapter 5, which survives as a fragment in ''Geographica'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Strabo/2D*.html Book II.4.1].</ref> of which he, Polybius, was skeptical. Despite Strabo's conviction of a lie, the perimeter said to have been given by Pytheas is not evidence of it. The issue of what he did say can never be settled until more fragments of Pytheas's writings are found.{{citation needed|date=April 2024}}