And thus was completed the reduction of the whole of North Asia, a territory of itself alone far more extensive than the European continent. In other respects there is, of course, no point of comparison between these two regions. This Siberian world, where vast wildernesses still remain to be explored, has a foreign trade surpassed by that of many a third-rate European seaport, such as Dover or Boulogne. Embracing a thirteenth part of the dry land on the surface of the globe, its population falls short of that of London alone; it is even more sparsely peopled than Caucasia and Turkestan, having little over one inhabitant to 1,000 acres. Accurate surveys of the physical features and frontier-lines are still far from complete. Only quite recently the first circumnavigation of the Old World round the northern shores of Siberia has been accomplished by the Swedish explorer, Nordenskjoeld. The early attempts made by Willoughby, Chancellor, and Burrough failed even to reach the Siberian coast. Hoping later on to reach China by ascending the Ob to the imaginary Lake Kitai--that is, Kathay, or China--the English renewed their efforts to discover the "north-east passage," and in 1580 two vessels, commanded by Arthur Ket and Charles Jackman, sailed for the Arctic Ocean; but they never got beyond the Kara Sea. The Dutch succeeded no better, none of the voyages undertaken by Barents and others between 1594 and 1597 reaching farther than the Spitzbergen and Novaya Zembla waters. Nor were these limits exceeded by Hendrick Hudson in 1608. This was the last attempt made by the navigators of West Europe; but the Russian traders and fishers of the White Sea were familiar with the routes to the Ob and Yenisei Gulfs, as is evident from a map published in 1600 by Boris Godunov. However, sixteen years afterwards the navigation of these waters was interdicted under pain of death, lest foreigners should discover the way to the Siberian coast. [Illustration: SIBERIAN NATIVES.]