There is nothing astonishing in these passages. The Polynesians knew perfectly well how to direct their course at sea by the stars, and the route from one point to another once observed was inscribed, if we may use the expression, in a song which would never be forgotten. They had a very correct general idea of the whole of their maritime world. The map drawn by Tupaïa, which I have reproduced in my book, is equal to those of our savants of the Middle Ages, while it embraces a considerable area. Tupaïa had seen for himself several of the islands which he represents. According to the calculations of Cook, he must have gone westward to a distance of 1,600 miles. But it was from the _sacred songs_ of his country that he acquired his knowledge of the rest of Polynesia, and was able to sketch it with tolerable accuracy. As to the _canoes_ in question, they were the same as the pirogues, which are mentioned by all travellers with admiration, and are declared by Cook to be very suitable for long voyages. This is a fact which is often established by the very precise details contained in some of the songs translated by Sir George Grey. We see, for example, one of the emigrant chiefs, Ngatoro-i-Rangi, “mount upon the roof of the hut constructed upon the platform which joined the two canoes.” We have only to add that the _Arawa_ and other similar vessels generally carried 140 warriors, and it will at once appear how devoid of foundation are the assertions of those writers who declare these voyages to have been impossible for want of sufficient means of transport. VI. The various documents which we now possess have not only been of service in proving beyond a doubt the general fact of migrations, and in acquainting us with the circumstances by which some of them were accompanied; they even enable us to indicate with very tolerable exactness the date of some of the most important. This result is generally obtained by the genealogies of the principal families. Each forms a kind of litany, which is sung in fixed rhythm, and of which each verse contains the name of a chief and those of his wife and son. Anyone, therefore, capable of remembering a song of one hundred verses may easily learn the longest of these genealogies. Confided to memory by the _Arepos_ or _Keepers of the Archives_, they were preserved with jealous care. Thomson informs us that in New Zealand a serious inquiry was made into these verbal documents, and their authenticity was so well established, that they have an equal value in matters of justice with our deeds.