One of the most interesting facts to the geographer concerning the Eskimos is their peculiar distribution. From choice or necessity they make their homes on the bleak, inhospitable northern border of the continent, and do not extend inland except where the coast is indented or large rivers enter the sea. In all localities their dwellings are near the water. They are the most northern people on the earth, and their still greater northward extension is checked only by the absence of land on which to build their winter homes. Their present inland limit on the continent is no doubt determined in part by long-established custom and by the distribution of the animals on which they have become dependent for food, clothing, fuel, etc., but the chief control formerly, no doubt, more potent than at present, is to be sought in the aggressiveness of the Indians. In Greenland, the arctic archipelago, and throughout the immense extent of coast-lands from Labrador to Alaska they have been isolated and withdrawn from contact with other peoples for a long period of time, and their slow development unmodified by extraneous influences. In Newfoundland and Alaska, however, they have been in contact with the Indians, trade relations established, and to a limited extent an interchange of ideas as well as some intermarriage has taken place. Throughout the vast extent of arctic coast between Newfoundland and Alaska, as well as in Greenland and on the islands of the arctic archipelago, the Eskimo was the sole inhabitant before the coming of Europeans, and one language current from the Atlantic to the Pacific. No other primitive people has such an extent in longitude. The reason for this peculiarity is that between the sea margin, where the Eskimo makes his home, and the southern border of the subarctic forest and adjacent prairies, where the Indians have their hunting-grounds, there intervenes the tundra--a neutral ground attractive neither to the Eskimo nor the Indian. The one thing which more than all else has enabled the Eskimo to maintain an existence and to thrive in the frozen north is his discovery of a means of obtaining heat and light where wood is scarce--that is, the invention of the lamp. This invention, as has been shown by Walter Hugh and others, was favoured by the occurrence in the far north of animals like the seal and walrus, which yield oil with a high heat-giving property.