The knowledge we possess regarding the navigable water to the east of Cape Chelyuskin towards the Lena, is mainly founded on the observations of the expeditions which were sent out by the Russian Government, before the middle of last century, to survey the northern part of Asia. In order to form a correct judgment of the results obtained, we must, while fully recognising the great courage, the extraordinary perseverance, and the power of bearing sufferings and overcoming difficulties of all kinds, which have always distinguished the Russian Polar explorers, always keep in mind that the voyages were carried out with small sailing-vessels of a build, which, according to modern requirements, is quite unsuitable for vessels intended for the open sea, and altogether too weak to stand collision with ice. They wanted, besides, not only the powerful auxiliary of our time, steam, but also a proper sail rig, fitted for actual manoeuvring, and were for the most part manned with crews from the banks of the Siberian rivers, who never before had seen the water of the ocean, experienced a high sea, or tried sailing among sea ice. When the requisite attention is given to these circumstances, it appears to me that the voyages referred to below show positively that even here we ought to be able during autumn to reckon upon a navigable sea. The expeditions along the coast, east of Cape Chelyuskin, started from the town Yakoutsk, on the bank of the Lena, in 62 deg. N.L., upwards of 900 miles from the mouth of the river. Here also were built the vessels which were used for these voyages.