Page:Siberia and the Exile System Vol 1.djvu/83

Rh rian pole of cold is at or near Verkhoyánsk. A long series of Russian observations made at this settlement shows the following mean temperatures: For the whole year, four degrees above zero Fahr.; mean temperature for December, 46 degrees below; for January, 55 degrees below; for February, 54 degrees below; or an average temperature of 51 degrees below zero for the three winter months. In 1869, the thermometer at Verkhoyánsk went repeatedly below -70 degrees, and fell once to -81 degrees Fahr.

Immediately south of the great northern túndra, and extending, with occasional breaks, from the Ural mountains to the Okhótsk sea, lies the second of the three zones into which I have provisionally divided Siberia—the zone of forests. As you go southward from the arctic ocean and get gradually into a less rigorous climate, trees begin to make their appearance. At first there are only a few stunted and storm-twisted larches struggling for existence on the edge of the túndra; but they gradually grow larger and more abundant, pines and firs make their appearance, then birch, willow, and poplar, until at last you enter a vast primeval forest, through which you may travel in a straight line for weeks together. This zone of forests has an area of hundreds of thousands of square miles, and stretches almost entirely across Siberia. Along its northern boundary the climate, although less rigorous than the climate of the túndra, is still severe; but long before you get through to its southern edge, the temperature grows milder, poplars, aspens, elms, and the Tatár maple take the places of firs,