While Caesar was still in Britain he had begun to collect materials for a description of the island and of the manners [Sidenote: Caesar’s description of Britain.] and customs of its inhabitants. Partly, indeed, it may have been based upon the account of the Greek historian, Timaeus, who had himself derived material from the journal of Pytheas;[1405] but certain sentences embodied the results of his own observation. What specially struck him as he marched through the country was the density of the population and the superiority in material civilization of the people of Kent. ‘The population,’ he wrote, ‘is immense: homesteads, closely resembling those of the Gauls, are met with at every turn; and cattle are very numerous.’[1406] His curiosity was excited by the statement, which he had seen in one of his Greek authorities, and the origin of which we have already endeavoured to trace,[1407] that in some of the islands off the mainland there was continuous night for a month about the winter solstice. ‘Our inquiries,’ he tells us, ‘could elicit no information on the subject; but by accurate measurements with a water-clock we ascertained that the nights were shorter than on the Continent.’[1408] It would be useless to guess from what authority he derived the puzzling statement that groups of ten or twelve men had wives in common, brothers sharing with one another and fathers with their sons;[1409] in other words, that one of the British customs was polyandry. Thoughtless commentators have condemned the passage as simply untrue: it has been explained as the outcome of a misunderstanding; and an eminent scholar, with a theory that needed every support, has insisted that it was merely a blundering description of the primitive institution of matriarchy, which he believed to have survived among the Picts of a later time.[1410] We can only be sure that neither matriarchy nor polyandry existed among the dominant Celts; but it is permissible to suppose that certain primitive communities in remote districts had some usage which gave colour to Caesar’s statement. But perhaps the most remarkable feature in his description was the approximate accuracy of his estimate of the size of the island. He was told that its circumference was two thousand miles; and this information was certainly not derived either directly or indirectly from Pytheas, whose estimate, if Strabo has reported it correctly, was monstrously exaggerated.[1411] On the other hand, Caesar, although, like Pytheas, he placed Ireland in its true position, imagined, in common with other geographers who derided Pytheas’s teaching, that the Gallic coast, from the Rhine to the Pyrenees, was roughly parallel with Southern Britain.[1412]