and Eratosthenes looked upon Pytheas with at least some respect. 

 What, exactly, do we know about the man? There is no doubt 

 of his abilities as an astronomer and mathematician ; even Strabo 

 allows him this, saying that "with regard to astronomy and mathe- 

 matical research he will appear to have used his data sensibly 

 enough." We are also told that Pytheas constructed a gnomon with 

 which he was able to fix the latitude of MassiHa so accurately that 

 it was not improved on for many centuries. At that time the Greek 

 method of working out latitude was based on the length of the 

 longest and shortest days of the year, and latitude was determined 

 by the number of hours the Sun appeared above the horizon. For 

 example, the farther north or south of the Equator you travel on 

 Midsummer Day, the longer the Sun remains above the horizon, 

 until finally you reach the Arctic Circle, where the Sun remains 

 above the horizon throughout the day. It was this method of 

 determining latitude that Pytheas himself used on his travels. 



Another contribution of Pytheas was that he contradicted the 

 belief that the celestial north pole coincided with a particular star. 

 Instead, he said that it was associated with a formation of three 

 stars. He was also the first Greek to observe and describe the 

 movements of ocean tides and relate spring and neap tides to 

 phases of the Moon, tides at that time being a phenomenon strange 

 to peoples living on the shores of the almost tideless Mediterranean. 

 While we have some knowledge of Pytheas himself, we know 

 practically nothing about his ship. We can presume that it was 

 seaworthy since it was bound for unknown northern waters, and 

 that it was equipped to defend itself against possible attack. Fridtjof 

 Nansen, one of the later explorers we will meet in this chapter, 

 suggested that it was probably more than a hundred feet long, and 

 in some ways better equipped than the Viking galleys that crossed 

 to Greenland and America about a.d. iooo. Sir Clements Markham, 

 president of the Royal Geographical Society at the turn of the 

 century, gave a detailed description of the type of ship she might 

 have been : a large trireme of four or five hundred tons, 1 5 o to 

 170 feet long. Although fitted with sails (yards with square sails 

 laced to them), she had auxiliary rowing power - 54 bottom rowers, 

 58 middle, and 62 upper, a total of 174. Such ships could average 

 fifty miles or more a day. 



Pytheas set out from Massiha, sailed through the Pillars of 

 Hercules, passed Cape St. Vincent and beyond the limit of the 

 world known to the Greeks. From there his course lay north. He 

 made his first recorded observation at a place where the longest 

 day was fifteen hours, which would be about the latitude of Oporto 

 (40° 5 9' N.). Continuing northward through the Bay of Biscay he 

 rounded Brittany and then crossed to Britain, either to Cantium 

 (Kent) or Belerium (Land's End), both of which he undoubtedly 

 visited at some stage of his circumnavigation of the whole of 

 Britain. Pytheas' description of Britain probably was taken origi- 

 nally from his book and reported by Diodorus : 



"This land is in shape triangular like Sicily, but its sides are not 

 equal; it stretches out along Europe slantwise, and they say that 

 the headland, which they call Cantium and which is least distant 

 from the Continent, is about 100 stadia [i Attic stadium = 607 

 English feet] from the land at the place the sea makes a current. 

 Another promontory, which is called Belerium, is said to be distant 



By the first century B.C. the tin miners 

 of Cornwall were casting tin in 150-pound 

 ingots. When the Phoenicians traded 

 with them earlier, the Britons had not yet 

 begun to use a furnace to smelt the ore. 



n«IIKKAT.\KON 



